No. 216.] 749 



made, and then dig in the manures with the subsoil, then put the 

 next spading of soil over the manure, and so on, so that the manure 

 ■will be about one spade in dt^pth from the surface. 



Dr. Underbill. I would put the subsoil on top. It is best to plough 

 subsoil up to the surface, it becomes dark mould in a short time. 



C. H. Hall. Manure at a moderate depth will remain dormant. It 

 must be near the surface in order to be affected by the heat of the 

 sun, or it cannot ascend. 



Dr. Underbill. Manure should be put as deep again in loose, po- 

 rous soils, as in stiff clay soils. iNothing ascends but the elements 

 in solution or gasified, and under the influence of heat. In our 

 country the solar heat is very powerful, but in England it is feeble, 

 only penetrating a few inches into the soil, I have recently visited 

 a valley of rich soil, which has been filled up with poor barren land 

 to the depth of from seven to fifteen feet, about seven years ago. 

 Now the growth on this once barren land is remarkably vigorous in 

 grape vines and plants of various kinds, much more so than on some 

 of the lands adjacent. No doubt the roots of the plants run down, 

 but here it is perfectly evident that the rich elements of the valley 

 beneath, ascend to the surface through the sand. 



When the winter breaks up in spring, the ground cracks, then 

 rains carry down some of the manure. I dig deep about my fruit 

 trees to let manure sink deep, and I find the best fruit on the trees 

 is derived from the lower roots which are deep, never on the lower 

 limbs which are supplied from those nearest the surface of the land. 

 The moisture at a depth is greatest. 



Mr. Hall, The best plan is to denude the limbs, and let in the 

 light of the sun. Too much top to a tree is not considered favora- 

 ble in England, it lessens the flavor of the fruit. Manure on the 

 surface or near it; it is not convenient if it is possible to put the ma- 

 nure several feet deep about trees or elsewhere. This question must 

 have further discussion. We must look into it fully. 



Judo^e Van \Vyck. The tendency of gas is upward, that of water 

 downward, and may carry down some of the elements ten or twenty 

 feet, out of the influence of the heat of the sun entirely. The Ce- 

 real grains cannot reach manures unless they are near the surface of 

 the soil. 



