163 



and I earnestly request the reader's atleiitiou, wliile I take 

 a rapid view of it. 



Pulverization, or the mechanical division of parts, is appli- 

 cable to all soils, in proportion to their adhesive texture ; as 

 even the most silicious, if not duly stirred, will become too 

 compact and dense for the admission of air, rain, and heat, 

 and, by consequence, for the free growth of plants. Strong 

 upland clays, not submitted to the plough, or the spade, will 

 in a few years be found in the possession of fibrous-rooted 

 perennial grasses, which form a clothing on their surface, or 

 of strong taprooted trees, such as the oak, which force their 

 way through the interior of the mass. For these reasons, 

 the first and great object should be, to give scope to the young 

 roots and fibres ; because, without fibres in abundance, no 

 woody plant can shoot freely, and develop its parts, whatever 

 be the richness of the soil. The fibrous roots, as has been 

 shown in Section IV., absorb the juices by means of intro- 

 susception ; but the quantity absorbed does not depend alone 

 on the quantity existing in the soil, but on the number of 

 the absorbing fibres. The more we can comminuate the 

 soil, the more those fibres will be increased, the more this 

 nourishment will be absorbed, and the more vigorous and 

 healthy tjie plant will become. 



Further : Comminution of parts increases capillary attrac- 

 tion, or the sponge-like property of soils, by which their hu- 

 midity is rendered more uniform, and more effective. It is 

 evident, that where the particles of earth are the most mi- 

 nutely divided, capillary attraction must be the greatest ; for 

 gravels and sands hardly retain water, while clays, not 

 opened by pulverization, 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 quan- 



