The journal of a naturalist / [Anon].

  • John Leonard Knapp
Date:
1829
Catalogue details

Licence: Public Domain Mark

Credit: The journal of a naturalist / [Anon]. Source: Wellcome Collection.

    44/474 (page 20)
    mon sand, but it was an expensive article! Tem- porary food for a crop may be found in animal, vegetable, or earthy manures, but these are ex- haustible ; and when aliment ceases, the crop pro- portionably diminishes. In one respect, chemical investigation may importantly aid the agriculturist, by pointing out the proportion of magnesian earth in certain limes used for manure, and thus indicate its beneficial or injurious effects on vegetation. I should not like lime containing 20 per cent. of this earth ; but when it contains a much smaller pro- portion, I should not think it very deleterious. This earth acts as a caustic to vegetation, and, neither being soluble in water, nor possessing the other virtues of lime, diminishes the number of bushels used according to its existence, and thus deprives the crop of that portion of benefit: but afterall, as Kirwan says, the secret processes of vegetation take place in the dark, exposed to the various and indeterminable influences of the at- mosphere ; and hence tke difficulty of determining on what peculiar circumstance success or failure depends, for the diversified experience of years alone can afford a rational foundation for solid and specific conclusions. The real goodness of a soil consists principally, perhaps, in the power it possesses of maintaining a certain degree of moisture ; for without this, the plant could have no power of deriving nutriment