The manures most advantageously applicable to the various sorts of soils, and the causes of their beneficial effect in each particular instance / By Richard Kirwan.

  • Richard Kirwan
Date:
1796
Catalogue details

Licence: Public Domain Mark

Credit: The manures most advantageously applicable to the various sorts of soils, and the causes of their beneficial effect in each particular instance / By Richard Kirwan. Source: Wellcome Collection.

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    [ So ] Mr. Young difcovered a remarkable circum- ftance attendant on fertile foils: he found that equal weights of ditierent (oils, being dried and reduced to powder, afforded quantities of air by diftillation fomewhat correfponding to the ratios of their values. This air was a mix- ture of fixed and inflamable airs, both proceed- ing, molt probably, from the decompofition of water by the coaly matter in the foil. The diftillation fhould be made from a retort glaz- ed on the outlide. He found an ounce of dry foil, value five (hillings, produced ten ounce meafures; Of value of from 5 to 12s. produced 28 oz. 12 —20 42 above 20 6-6 This appears to be a good method of eftima- ting the proportion of coaly matter in toils that are in full heart; that is, not exhauited, and freed from roots, &c, Another mark of the goodnefs of a foil is the length of the roots of wheat growing in it; for thefe are an inverie proportion to each other, as, if the land be poor, the wheat will extend its roots to a great diftance in queft of food; whereas, if it be ncn, t]aey will not extend above five or fix inches; but