116 Snoiv-Plough for Walks and Footpaths. 



imagine, like some in these days, that plants derive the chief, if not the whole, 

 of their nourishment from the atmosphere.* They are thus nourished in 

 great measure ; but, unless they are supported also from the soil by means of 

 their roots, what they obtain from the air will be of no avail. Vegetables, in 

 this respect, are like animals ; and if any one were to try the experiment on 

 himself, whether he could live upon air alone, he would find out his mistake 

 sooner than Tull discovered that pulverising the soil would not enable him to 

 dispense with manure. I may observe that Mr. Bick's alleged discovery of 

 the cultivation of the ground without the aid of manure will, in the end, prove 

 like Tull's. 



The effect of manure on soil is pretty well understood ; but not so how 

 land becomes exhausted by a series of crops of the same kind, so that its lost 

 powers cannot be renewed by manuring. It is a common opinion that each 

 kind of plant draws something from the soil peculiar to itself. Of course this 

 cannot be meant of all the 44,000 kinds already discovered. But, if it be 

 supposed that only a few species act on the soil in this manner, we may still 

 ask how it happens that natural forests are never exhausted. The soil con- 

 tinues good, though it rears a series of trees of the same kind from generation 

 to generation. This fertility may be owing to the annual decay of the leaves, 

 twigs, &c., which fall from the trees, and are mixed up finally with the soil. 

 If it were practical to allow the annual decaying crops to do so, I question if 

 the soil would become exhausted. That there are now wastes, even in this 

 country, which were once covered with trees, does not invalidate my state- 

 ment. I have not, indeed, sufficient evidence to decide how they became 

 what they now are; but sufficient proof exists that the trees fell in full 

 vigour. Even the oak seems to have been once flourishing in the North of 

 Scotland : the root end of one, 6 ft. in circumference, found on the summit of 

 Corryarrack, in Inverness-shire, is evidence of this; and the thriving growth of 

 young plantations in such parts is convincing proof that there is no fault in 

 the soil. I may instance those of Lord Methven on Methven Muir. 



This may be supposed to fall in with the opinion, that nothing but rest can 

 restore the lost energies of the soil. Certainly those wastes have been long 

 at rest ; but a state of rest may be understood in two different ways. Soil 

 may be said to rest, in one sense, when no crop is upon it, and the soil is 

 pulverised and left fallow ; in another, when not disturbed, but left to the 

 natural growth of grass. By the first, it is asserted that " fresh alkalies are 

 set free from the rock." This may be correct; but it cannot be truly said of 

 the second state of rest, in which the soil is not exposed to atmospheric 

 action and influence. Nevertheless, this latter plan is often practised with 

 great success; and this has probably led to the mixing of the turf, or rather 

 the top spit or sod, from pasture land, with exhausted soil, in preference to 

 all other kinds of manure. 



Cossey Hall Gardens, near Korwich, Feb. 8. 1843. 



Art. VI. Notice of a Snow- Plough for Walks and Footpaths. By 



John Lamb. 



As I do not recollect having seen, in any of your works on gardening, a snow- 

 plough for walks or footpaths, I beg to give a description of one {fig. 12.) 

 made here during the present snow, which answers well. It is simple in its 



* Liebig mentions that a large proportion of the solid matter of plants is 

 derived from the atmosphere. 



