This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1876 Excerpt: ...as compared with the combustible parts, is small; though during the life of the tree, in the chemical processes of decomposition, elaboration, and assimilation, their effects may be very great. The combustible or organic parts of trees, though they are not soil, are absorbed by the roots from the soil; that is, their ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1876 Excerpt: ...as compared with the combustible parts, is small; though during the life of the tree, in the chemical processes of decomposition, elaboration, and assimilation, their effects may be very great. The combustible or organic parts of trees, though they are not soil, are absorbed by the roots from the soil; that is, their constituents are elaborated or chemically prepared for the plant in the soil, and absorbed by the roots from the soil. But as neither animals nor plants bring anything into the world with them, so neither of them take anything away with them; and if their remains are restored to the soil, no impoverishment will take place. I have no faith in the supposed excretion from the Boots do not excrete. roots of substances unnecessary to the growth of the tree. If this were so, the roots would soon be surrounded with such substances, and would be incapable of absorbing nutriment. In chalk districts eternal woods are found composed of nothing but beech; in other soils, of nothing but oak. The oldest vineyards and the oldest hop-gardens are the best. And how many millions of acres are in this world covered with perpetual heath! In all these cases, if the roots excreted substances unfit for nourishing the plants, the whole soil would have become saturated with them. Land plants grown in water are always unhealthy. Under these circumstances, may not colouring matter, or other substances supposed by Macaire-Princep to be excretion, be the result of disease and decay or partial maceration of the roots. There is no discoloration of the water in which the seedlings of forest-trees are made to grow, while these are in health. I imagine that trees, in absorbing by their roots the moisture with which they come in contact, give off the unnecessary parts of this by ...
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