CHEMISTRY. SOIL. 



345 



one of these days, we will arrange a series of ihem from the various branches of 

 agricultural literature — ay, for Agriculture has its literature. 



We beg pardon of the reader fox dwelling so long on one topic, and promise 

 not soon to oflend in like manner again. But the fact is that we are so thoroughly 

 convinced that almost all wide-spread, enduring and honorable improvement for 

 Agriculture now lies in that direction, that our feelings run away, perhaps, with 

 our judgment, so that we are half persuaded that it would even be not unbecom- 

 ing in our pulpit orators to pronounce an occasional discourse on the duties and 

 occupations of rural life, the high accomplishments that properly belong to it, 

 and its tendency to foster sentiments of benevolence toward every living thing, 

 and reverence for the great Creator of all. 



Sell-love thus [nislied to social, to divine, 



Gives thee to make thy neighbor's blessing thine. 



Is this too little for the boundless heart/ 



Extend it — let thy enemies have part: 



Grasp the whole worlds of reason, life and sense 



In one closti system of bcncvolenee : 



Ha[>pier as kinder, in vvhate'er degree, 



And hight of bliss but bight of charity. 



And now for our recitations, which we take from the works and materials sup- 

 plied by able writers, from whom we are making up The Farml-rs' Library. 



SOIL 



ITS NATUnE AND ITS OFFICES. 



The soil is formed by the decomposition 

 of the minerals, of which the cnist of the 

 globe consists. The water which flows over 

 the surface is absorbed into the ])ores and 

 fissures of the rocks ; and in winter, on 

 freezing, it expands with sncli irresistible 

 force as to crumble down even the materials 

 of the densest and hardest stone. The pul- 

 venileut or gravelly material so afforded, is 

 carried down by rains or floods to the lower 

 grounds, and spreading over the more level 

 country forms the cultivable soil. Inde- 

 pendent of the mechanical action of water, 

 the constitution of numei'ons rocks is such as 

 to cause their gradual decoinjiosition by its 

 chemical action, as in the case of felspar anil 

 other minerals ; and by the direct action of 

 the atmosphere, all rocks which contain pro- 

 toxide of iron very rapidly decompose and 

 crumble down. Such being the origin of the 

 soil, its constitution will be easily understood 

 to depend on that of the rock from which it 

 has been formed; and as on this constitution 

 its fertility or its power of supplying plants 

 with the materials they re(|uire for tlieir 

 growth, mainly depends, it will be seen that 

 the agricidtural capabilities of a country are 

 immediately connected with, and dependent 

 on, its geological charac;ter. A district of 

 which the rock is simple in constitution can- 

 not furnish a fertile soil. A pure quartz rock, 

 or a pure limestone, could only furnish fioin 

 Its soil to plants, lime or silica, and they 

 should hence languish for want of other 

 equally imporUmt elements. The edges of a 

 geological district, where various rocks are 

 m coutict, will, therefore, always be more 

 fertile as to soil than its interior, and the more 

 uumcrous the rocks in the ueighborhood, 

 (729) 



and the greater the diversity in their mineral 

 character, the more complex will be the soil 

 furnished by tlieir decomposition, and by its 

 power of furnishing the elements of growth 

 to dirtereut khids of plants, the greater will 

 be the range and energy of its fertility. * * * 

 The office of the soil is not merely to afford 

 such chemical elements as the constitution of 

 the plant requires, but also, and what, in an 

 agricultural [)oint of view, is nearly of as great 

 importance, to afford a mechanical support to 

 the plant during its existence. This support 

 must be consonant to the habits and structure 

 of t!ie plant, and hence is the special classifi- 

 cation of soils, as adapted for the cultivation 

 of various kinds of crops, quite independent 

 so far of their chemical coni[)ositi(ni. Thus 

 if we take a tenacious clay, which, when drj-, 

 becomes hard and solid, and when wet forms 

 an impervious paste, it is evident that plants 

 which either required to extend delicate roots 

 to a distance, or to generate a single root of 

 considerable bidk, could not grow there in a 

 hccdthy maimer; while a light and very 

 porous soil would be adapted natiii-ally for 

 such crops. On the other hand, a plant of 

 which but little stretches under ground, the 

 stem and other portions presenting a consid- 

 erable mass and surface to the air, would find 

 in a tenacious clay a sure anchorage and sup- 

 port against the effects of the wind and rain. 

 It is thus that wheat and turnip soils are al- 

 most synonymous with stiff and adhesive 

 clays on the one hand, light and friable loams 

 upon the other, and similar instances of the 

 mechanical adaptation of soils to agricultural 

 practices will have occuired in the experience 

 of every practical farmer. 



It is not merely, however, in tliis mechan- 



