1 Noy., 1898.] QUEENSLAND AGRICULTURAL JOURNAL. 365 
H. ©. Prinsen Geerligs* has conducted important experiments at the West 
Java Experiment Station, regarding the conversion of organic nitrogen into 
ammonia and nitric acid, the results of which are given in the following table :— 
From 100 parts of nitrogen contained in oil-cakes and in sulphate of 
ammonia were formed in the soil— ee 
{ 
Old Mouldy Fresh Home-pressed| Chinese Soja-bean Sulphate of 
The oil-cakes contained— - Earth-nut Cakes. Earth-nut Cakes. Cakes, Asainonta’ 
Nitrogen... ah e 5°88 per cent. 4°03 per cent. 7°10 per cent. 
Fat .. sh) toe ata 10°17 ” 20°37 om 11°80 ue 
Ashes fey see vee | 19:20 —C,, 10:80, S09 Beas 
gin g(a a\a 3 
Peep EP eS i) ih o | 8 | 2 3 | a 
|e eps dirs I Ebabe ener eens at et ie 4 
era Apa Se Sha Ge She SEP Pe) BS EP BE LS he 
After] month ... we | 48] 23:7] 641] 7:4] 6:0 | 2771 | 62:1] 4:8] 2°7 | 36°7 | 51-6 | 10-0 | 15°3 | 82°9 | 1°8 
ayn eS 7 ty .. }19°6 | 17-4 | 51-9 | 11:1 | 20°0 | 16°7 | 53°8 | 9-5 | 14°9 | 81°9 | 41+1 | 12-1 | 47-4 | 611 | 15 
Ty PR! n .|52°6] 1°7-| 28°21 18 5 | 443 . | Alek | 143 | 27-9 | 21°5 | 38°5 | 12:1 | 89-4] 8-0} 2°6 
| 4) ” . | 544) 8:5] 118 | 25°31 72°4) 3:8) 9:9) 143] 70°38] 4:8 | 12°8 | 12-1 
Tee ae - | 63:7] 0-4 | 10-6 | 25°3 | 85°1 0°6 | 14°3| 77:9} 0-9} 61) 121 
Ma Ee) .{70°4) 0:7] 36] 25°3] ... . | a. 1852] 0-7} 2:0] 12-1 
| 
From the above figures the following conclusions can be drawn :— 
1. Fresh oil-cakes decompose more rapidly than old ones. 
2. A difference in the percentage of fat is immaterial, as this material 
does not prevent the formation of nitrate. 
8. Sulphate of ammonia is converted into nitrogen, in the form of 
nitrate, in the course of three months, without suffering any great loss. 
4, Organic (albuminous) nitrogen is gradually converted, by putrefaction, 
into ammonia, and into nitrogen in the form of nitrate. Available nitrogen is 
formed in nine months. 
5. Under the most favourable circumstances, only 85 per cent. of the 
nitrogen contained in oil-cakes is available to the plant. The loss is much 
greater in the case of mouldy cakes, only 70 per cent. being converted into 
nitrate. 
6. In the tropics the availability of nitrogen in good oil-cakes is some- 
what greater than Prof. Wagner’s figures, so that, in general, a somewhat 
higher availability of organic nitrogen may be reckoned upon. However, as 
before shown, differences may occur in proportion as the fertilisers decompose 
more or less easily. 
II. Puospuaric FKEerrinisers. 
1. Phosphoric acid, soluble in water—as furnished in acid phosphate, 
containing 14 to 21 per cent. phosphoric acid—is the most assimilable form of 
this plant-food ingredient. The acid phosphate is manufactured by decompos- 
ing slowly soluble crude phosphates by means of sulphuric acid. When liquid 
phosphoric acid is employed tv decompose the crude phosphates, we obtain 
so-called double superphosphate, containing 35 to 45 per cent. of phosphoric 
acid, soluble in water. The latter material should be used wherever fertilisers 
have to be brought from a distance, as its cost is but little higher, and the 
freight charges only half as much. 
2. The phosphoric acid contained in Thomas’ slag is not soluble in water, 
but is very effective, so that we are correct when we say that the phosphoric 
acid is soluble in the soil. Experiments conducted by Prof. Wagner, Darm- 
stadt, Prof. Maercker, Halle a. S. and others, haye proven that the phosphoric 
acid soluble in a given solution of citric acid produces the same effect as that 
soluble in water. However, as the solubility in citric acid of the different 
* HL, C, Prinsen Geerligs: ‘‘Jets over de Bemesting van het suikerriet,” Archief vor de Jaya- 
Suikerindustrie 18 
