THE PLANTER S GUIDE. 



133 



being thereby chilled, should prevent trenching from 

 being always executed as deep as possible. 



The surprising changes worked on all soils, in conse- 

 quence of a minute comminution of their parts, and the 

 various ways in which it increases fertihty, have only of 

 late years been communicated to agriculture, by chemical 

 analysis and investigation ; so that there is the less 

 wonder that they should, in a great measure, have escaped 

 the planter's notice. If the process be important in 

 general to woody plants, it must be greatly more impor- 

 tant to subjects meant for removal ; and I earnestly 

 request the reader's attention, while I take a rapid view 

 of it. 



Pulverisation, or the mechanical division of parts, is 

 applicable to all soils in proportion to their adhesive 

 textm^e ; 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 in- 

 terior 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 in- 

 trosusception ; 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 com- 

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



