134 



THE planter's GUIDE. 



the more this nourisliinent will be absorbed, and the more 

 vigorous and healthy the plant will become. 



Further, comminution of parts increases capillary 

 attraction, or the sponge-like property of soils, by which 

 their humidity is rendered more uniform and more effective. 

 It is evident that, where the particles of earth are the 

 most minutely divided, capillary attraction must be the 

 greatest ; for gravels and sands hardly retain water, while 

 clays not opened by pulverisation either do not absorb 

 water at all, or, when by long action it is absorbed in a 

 superabundant quantity, it is not readily discharged. 

 Water is necessary to the growth of plants : it is essential 

 to the juices or extract of the vegetable matter which they 

 contain ; and unless the soil, by means of comminution, be 

 fitted to retain the quantity of water requisite to produce 

 those juices, the addition of manure will be useless. 

 Manure is ineffectual towards vegetation until it become 

 soluble in water, and it would remain useless in a state 

 of solution if it so abounded as utterly to exclude air ; 

 for in that case the fibres or mouths of plants would be 

 unable to perform their functions, and they would soon 

 drop off by decay. 



The temperature of soils, which few planters take into 

 their consideration, is singularly improved by their being 

 pulverised. Earths, as Griesenthwaite remarks, are among 

 the worst conductors of heat which we know ; consequent- 

 ly it would require a considerable time ere the gradually 

 increasing temperature of spring could communicate its 

 genial warmth to the roots of plants, if their lower parts 

 were not heated by other means. To remove this defect, 

 which always belongs to a close or dense soil, it is essen- 

 tially necessary to have the land open, so that there may be 

 a free ingress to the genial air and tepid rains of spring. 



