----------------------------+------+------+------+------+------+------ |No. 1.|No. 2.|No. 3.|No. 4.|No. 5.|No. 6. ----------------------------+------+------+------+------+------+------ Ammonia in 1,000 grains | | | | | | of natural soil | 0.293| 0.181| 0.085| 0.109| 0.127| 0.083 Ammonia in 1,000 grains | | | | | | of soil after liming | 0.169| 0.102| 0.040| 0.050| ... | 0.051 Ammonia in 1,000 grains of | | | | | | soil after liming and | | | | | | exposure to the vapor | | | | | | of ammonia | 2.226| 2.066| 3.297| 1.076| 3.265| 1.827 Ammonia in 1,000 grains | | | | | | of soil after exposure to | | | | | | ammonia without liming. | 1.906| 2.557| 3.286| 1.097| 2.615| 2.028 ----------------------------+------+------+------+------+------+------ No. 1. Surface soil of London clay. No. 2. Same soil from 1½ to 2 feet below the surface. No. 3. Same soil 3½ feet below the surface. No. 4. Loam of tertiary drift 4 feet below the surface. No. 5. Gault clay--surface soil. No. 6. Gault clay 4 feet below the surface. It is evident that lime neither assisted nor interfered with the absorption of ammonia, and hence the beneficial effect of liming on such soils must be accounted for on some other supposition. This negative result, however, does not disprove the truth of Prof. Way’s hypothesis, for it may be that the silicate salt in the natural soils was that of lime and not that of soda. Indeed, the extent to which the natural soils absorbed ammonia--equal, in No. 3, to about 7,000 lbs. of ammonia per acre, equivalent to the quantity contained in 700 tons of barn-yard manure--shows this to have been the case. _The lime liberated one-half the ammonia contained in the soil._ “This result,” says Prof. Way, “is so nearly the same in all cases, that we are justified in believing it to be due to some special cause, and probably it arises from the existence of some compound silicates containing ammonia, of which lime under the circumstances can replace one-half--forming, for instance, a double silicate of alumina, with half lime and half ammonia--such compounds are not unusual or new to the chemist.” This loss of ammonia from a heavy dressing of lime is very great. A soil five inches deep, weighs, in round numbers, 500 tons, or 1,000,000 lbs. The soil, No. 1, contained .0293 per cent of ammonia, or in an acre, five inches deep, 293 lbs. After liming, it contained .0169 per cent, or in an acre, five inches deep, 169 lbs. The loss by liming is 124 lbs. of ammonia per acre. This is equal to the quantity contained in 1200 lbs. of good Peruvian guano, or 12½ tons of barn-yard manure.