FERTILIZERS. 795 



organic dry matter, 4,2 lbs. of nitrogen, 1.5 lbs. of pliosplioric acid, and 

 4.4 lbs. of potash per acre. The roots and vines grown on an acre con- 

 tained a total of 34.8 lbs. of nitrogen, 18.8 lbs. of phosphoric acid, and 

 54.8 lbs. of potash. The nitrogen in the vines is eqnivalent to that 

 contained in 437i lbs. of nitrate of soda, and is valned at about $11. 



Report of pot experiments -with phosphates, W. H. Bishop 

 [Delaware Sta. Rpt. 1893, pp. 193-202, figs. 2). 



Synopsis. — In comparative tests of soft Florida pbosphato, crude iron and alumina 

 phosphate, concentrated iron and alumina phosphate, and acid phosphate, com- 

 bined with nitrate of soda and muriate of potash onsoja beans grown in 3 series 

 of pots containing (1) 16 lbs. of clayey soil, (2) 20 lbs. of sandy soil, and (3) 20 

 lbs. of ground quartz, the first two phosphates gave no increase in crop; the 

 last two increased the yields equally. 



The soft Florida phosphate used contained 28.81 per cent of insolu- 

 ble phosphoric acid, the "raw ground rock" (iron and alumina phos- 

 ])hate) 36 to 38 per cent of insoluble phosphoric acid, the concentrated 

 phosphate (of iron and alumina) 38 to 40 per cent of available phos- 

 phoric acid and 49 to 50 per cent of total phosphoric acid, and the acid 

 phosphate 15 per cent of phosphoric acid. These were each applied, at 

 rates furnishing the same amounts of phosphoric acid, in combination 

 with muriate of potash and nitrate of soda, in 3 series of galvanized 

 iron pots containing different kinds of soil, viz, a clayey soil from the 

 station grounds (10 lbs. per pot), a sandy soil from near Dover, Dela- 

 ware (20 lbs. per pot), and ground quartz (20 lbs, per pot). In case of 

 the sandy and clayey soils an additional pound of sand was added to 

 the surface of each pot. For comparison some of the pots received 

 gypsum alone and combined with muriate of potash and nitrate of 

 soda, and others received no fertilizer. The soils were carefully mixed 

 and sifted and the fertilizers thoroughly incori^oratedwith them. Soja 

 bean was the plant used. The pots were watered when it seemed nec- 

 essary, the amount of water applied at each watering being 70 per cent 

 of that which the soil would hold at saturation. The tabulated data 

 show fo*: each series the kind and amounts of diiferent fertilizers 

 applied, the water added, and the yields of stems (without leaves) 

 and beans on each duplicate plat and the average yields. 



The conclusions reached were as follows: 



" (1) Soft Florida phosphate and ' raw ground rock' (iron and alumina phosphate) 

 gave no increase in the crop. 



" (2) 'Concentrated phosphate' gave as good results as acid phosphate. 



"(3) When a full supply of water is added to soil that is already in a fair state 

 of fertility the differences in the crop produced by the addition of fertilizers, even 

 in large quantities, are not very great." 



Methods of preparing phosphates of alkalies from phosphates 

 of lime and iron, E, A. Schbider [Chem. Ztg., 19 {1895), No. 10, Repert., 

 p. 34; Ztsehr. angew. Chem., 1895, No. 4, p. 109). — The following method 

 is applicable to natural phosphates of lime, Thomas slag, and phos- 

 phates rich in iron oxid. The phosphate is dissolved in sul[)huric acid, 



