Essay on the Analysis of Soils] 



47 



proportions of the simple eartlis of wliicli it is composed. Thus, 

 a sandy or siliceous soil, of wliicli the particles are extremely mi- 

 nute, readily diffused through water, and slowly deposited, ap- 

 proaches to the nature of a clay-loam, being- retentive of water, 

 and binding in drying. The hard particles of argillaceous or 

 calcareous stones, on the other hand, according to their size, have 

 qualities very analogous to siliceous gravel or sand, the chemical 

 properties of the earths not coming into action, except by means 

 of other chemical agents. But the organic portion of the soil, 

 which arises from the decomposition of animal and vegetable sub- 

 stances, has the greatest influence on the fertility, by modifying 

 the effects of sand or clay, and furnishing the real nutriment of 

 plants by its action with light, heat, air, and moisture. It appears 

 from this that the chief object, in a practical agricultural analysis 

 of a soil, is to ascertain the relative size of the particles of which 

 it is composed, their chemical nature, their affinity to moisture, 

 and the quantity of organic matter intimately blended with the 

 earths. Any adventitious substances which may influence the 

 fertility ought to be detected, if possible ; but, unless these are in 

 a sufficient quantity to produce a decided effect, they may in ge- 

 neral be neglected. 



It must be kept in mind that it is not a chemical nor a mine- 

 ralogical analysis which is attempted to be described : it is a mere 

 examination of the soil, which may be sufficient for the purposes 

 of the farmer, and which the man of science may carry on to any 

 extent and accuracy : we will only carry it so far as can be fol- 

 lowed by any man of common information, however deficient in 

 chemical knowledge. 



We proceed to the description of the process we recommend. 

 The soil to be examined must be taken a few inches under the 

 surface, and in different parts of a field. If there appears much 

 uniformity, the portions may be mixed, in order to have the 

 average quality of the soil: should there be a visible difference 

 between one portion and another^ which is often the case, each 

 may be analysed separately. 



A portion of the earth to be analysed is dried in the sun or near 

 a fire, until it feels quite dry in the hand. It is then reduced to 

 powder by the fingers, or by rolling it on a deal board with a 

 wooden roller, so as to separate the particles, but not to grind 

 them : any small stones above the size of a pea must be taken 

 out. If these form a considerable part of the soil, their propor- 

 tion must be ascertained by weight ; their nature and quality may 

 be afterwards examined. This being a very simple operation, and 

 obvious to the sight, need not be described. Where the stones 

 and pebbles are evidently accidental, they may be overlooked, as 

 having little influence on the fertility. The dry earth, cleared 



