Practical papers —soils. 
367 
have constantly increased its strength and producing power. The 
strong and vigorous roots of the trees penetrate the soil to a great 
depth, drawing sustenance from beneath adapted to their growth 
and full development; their leaves annually put forth, acting as 
lungs during their period of growth, receiving food from the earth 
by the circulation then constantly going on, and in the autumn, 
fall to the earth, furnishing organic matter to still further increase 
the richness and fertility of the soil. So with the grasses. They 
grow luxuriantly through each successive season, fed by the fertil¬ 
izing properties of the soil adapted to their wants, and in due 
season return to the soil, producing a vegetable mould which en¬ 
riches and strengthens it, so that a more vigorous plant follows the 
ensuing year. Thus nature produces natural products, returning 
each year all she produces, except the increased growth of the 
trees and the increased weight of the animals which feed upon her 
products ; and they, too, after having fulfilled the mission for 
which they were created, return to the earth those elements of which 
they are composed, to be again converted into plant food. But, 
says one, the tree has long, strong and vigorous roots capable of 
penetrating the soil to great depths in search of food, and that lit¬ 
tle of the strength of the surface soil is taken, while the fine root¬ 
lets of the cereals, and most other cultivated products cannot pern 
etrate beyond that depth which is made mellow and friable by 
cultivation, and hence must derive most of their food from near 
the surface. 
This, to a great extent, is true, and before I close this paper, I 
shall have occasion to speak of the importance of clover, which, . 
in my judgment, does for the farmer what the tree of the forest 
does in nature, brings up from depths below, fertilizing properties 
which otherwise could not be reached. Some scientific writers in¬ 
form us that plant food is much of it derived directly from the 
atmosphere, but from observation, I am of the opinion that this 
theory is not well supported by either experience or the natural 
laws which govern the growth of plants, animals or men. While 
it is possible for the foliage of plants to absorb certain fertilizing 
gases from the atmosphere, it is equally true that animals, and 
even human beings may receive nutriment by the same process, 
and yet it does not naturally follow that such is the channel 
