1846.] Analysis of Soils. 221 



the fine slime may be peured off, and more water may be pou'^d 

 on the coarse matter, and by several decantations the finer matter 

 will be washed away, and the water will come off quite clear. 

 This method is very instructive, for we very readily perceive the 

 minerals of the soil in the clean particles that remain. 



It is convenient in a mechanical analysis of soil to operate on 

 about 1000 grs. of the dry soil. Inspect carefully the various 

 minerals of which the gravel, sand and washed loam consist, for 

 the coarser particles are those which would become fine soil by 

 disintegration and decomposition, and therefore indicate the sup- 

 ply that may be expected. Thus mica and felspar are minerals 

 filled with potash and soda, and by the action of carbonic acid 

 from decayed plants, and the organic acids of the soil, they are 

 made to yield their alkaline matters and suffer decomposition. 

 Carbonate of lime or limestone also yields to decomposing vegeta- 

 ble matters and forms soluble salts. It also takes the sulphuric 

 acid from generating copperas as it forms from iron pyrites, and 

 forms gypsum, while the diminished carbonic acid either goes to 

 dissolve part of the carbonate of lime as a bi-carbonate, or rises 

 as a gaseous emanation, and is absorbed by the foliage. The 

 above remarks are all we have time now to add to this section ol 

 our analysis. Reflecting men will discover many other advanta- 

 ges of the mechanical examination of soils, and we leave the 

 subject for their consideration. 



2. Chemical Analysis of Soils. 



Chemistry investigates the nature of soils more minutely than 

 any other science, for by the chemist's art all the hidden proper- 

 ties are brought out and fully exposed. He deals with atoms in- 

 visible even to the most powerful microscopes, and the laws of 

 their combination are by him at once discovered. It is the ap- 

 plication of this science to agriculture that is to redeem it from 

 empyricism and guess-work; and when farmers have advanced 

 far enough in science to understand the work of the chemist, they 

 will have made a gigantic stride in the improvement of their art. 

 I would not endeavor to make any one believe that in the pre- 



