210 ELEMENTS OF THE AIR. 



boundless luxuriance of vegetable growth. Light arid 

 air, heat and water, are the sources of vitality, and they 

 become incorporated, as it were, or assume a tangible 

 form, in the green masses produced in the surface of the 

 earth; and these, in decaying, constantly increase the fer- 

 tility of the soil, because they not only restore to it the 

 inorganic substances which they took from it, but many 

 others which they drew from the atmosphere, and em- 

 bodied in their leaves, and stalks, and roots. 



The atmosphere is known to be full of the very ele- 

 ments which it is most desirable to secure and turn to 

 our own use ; and there is no way in which the farmer 

 can avail himself of these invaluable aids so surely as 

 by embodying them in the form of green vegetable 

 masses, and turning them fresh beneath the surface, 

 where they soon decay, and are ready to nourish other 

 vegetable bodies, that is, to produce crops which are of 

 money value. 



Green manuring has rarely, or never, failed of pro- 

 ducing satisfactory results, when it has been economi- 

 cally and judiciously applied ; and its value as the true 

 mode of fertilizing the earth has been sufficiently proved 

 in practice, in cases where the farmer has ploughed in 

 ^clover, buckwheat, oats, &c. The result or effect of 

 green manuring is well known, and the truth of the sys- 

 tem is sufficiently shown in the fact that it is strictly in 

 accordance with nature. 



But our ordinary modes have usually been too expen- 

 sive, either on account of the cost of the seed of the 

 -clovers or other large seeds, or in causing the loss of 

 rthe crop for the year, that is, in fallowing ; or in failing 

 to secure the full benefit of the system, from the use of 

 too few varieties or species of plants, and consequently 

 having too small a mass of vegetable matter ; yet, not- 

 withstanding this failure to secure the highest advan- 



