Phosphatic Manures for Root-Crops. 49 
bone-earth is here absorbed in a much larger ratio than by 
the red loam.) 
After 8 days (the bottle now containing 19,250 grains of water), 7000 grains of 
the liquid being filtered otY, were found to contain only 
•23 grains of bone phosphate. Hence the 19,250 grains of 
water held in solution only '63 grains. Therefore, after 
8 days, the soil had altogether absorbed 7S-31 grains of bone 
phosphate. 
After 26 days the liquid was found to contain no appreciable amount of bone- 
earth. 
Supposing the ufiole Solution to have been drawn off in each stage of the ■ 
Hxperiment, it icould have contained — 
Grains. 
After 24 hours S'36 of soluble phosphate. 
„ 8 days "86 „ 
„ 2G days none. 
And tlie soil would have absorbed — 
Grains. 
Aiter 24 hours 72-81 
„ 8 days 80-31 
„ 26 days 81-17 or the whole amount of 
soluble phosphate. 
Thus the chalkvsoil absorbed the soluble phosphate much more 
rapidlv and perfectlv than the loam, which contained but little 
lime. ^ et even in the presence of a great excess of finelv-divided 
carbonate of lime the absorption of the soluble phosphate is not 
instantaneous, nor is it completed in twenty-four hours. In both 
sets of experiments the same relative proportions of soil, water, and 
soluble phosphate were employed ; the results are therefore strictlv 
compartible. 
Absorption of Soluble Phosphate by a stiff Clay Subsoil. 
Experiment C. — I next selected some very stiff Essex clav, 
sent to me some time ago for examination bv !Mr. Mechi, of 
Tiptree Hall, considering that such a choice would afford a 
useful contrast and standard of comparison with the preceding 
experiments. 
100 parts of this subsoil in an air-dry condition contained : — 
Moisture D-46 
Water of combination and a little organic matter . . 4-S7 
Oxides of iron and alumina 17-38 
Phosphoric acid -06 
Carbonate of lime 1-02 
Sulphate of lime -13 
Magnesia -92 
Alkalies and leys -45 
Insoluble siliceous matters (clay) 65-71 
HX>-00 
VOL. XXIV. E 
