35 ANALYSfS OF SOILS. 



The next procefs, however, after that of heating, ftiould be 

 their reparation, which may be eafily accompli (lied by the 

 fieve, alter the foil has been gently bruifed in a mortar. The 

 weights of the vegetable fibres or wood, and of the gravel 

 and (tones (hould be feparately noted down, and the nature 

 of the laft afcertained; if calcareous, they will eflfervefce with 

 acids ; if filiceous, they will be fufficiently hard to fcratcfy 

 glafs ; and if of the common aluminous clafs of ftones, they 

 will be foft, eafily fcratched with a knife, and incapable pf 

 effervefcing wiih acids. 



VII. Separation of the Sand and Clay, or Loam k from each 



other. 

 Sand, day, and The greater number of foils, befides gravel and ftones, con- 

 fr-m eTh^other ta ' n ' ar g er or fmal'er proportions of fand of different degrees 

 by eluiriation. of finenefs ; and it is a neceffary operation, the next in the 

 procefs of analyfis, to detach them from the parts in a ftate 

 of more minute divifjon, fuch as clay, loam, marie, and ve- 

 getable and animal matter. This may be effected in a way 

 fufficiently accurate, by agitation of the foil in water. In this 

 cafe, the coarfe (and will generally feparate in a minute, and 

 the finer in two or three minutes, whilft ihe minutely divided 

 earthy, animal, or vegetable matter will remain in a ftate of 

 mechanical fufpenfion for a much longer time; fo that by 

 pouring the water from the bottom of the veffel, after one, 

 two, or three minutes, the fand will be principally feparated 

 from the other fubftances, which, with the water containing 

 them, mud be poured into a filter, and after the water has 

 pafled through, collected, dried and weighed. The fand muft 

 Jikewife be weighed, and their refpeclive quantities noted 

 down. The water of lixiviation muft be prelerved, as it 

 will be found to contain the faline matter, and the foluble 

 animal or vegetable matters, if any exift in the foil. 



VIII. Examination of the Sand, 



The fand fc?a- By the procefs of warning and filtration, the foil is feparated 



cLVLd ca-ci- ' nto two P ortions » the moft important of which is generally the 



reous. finely divided matter. A minute analyfis of the fand is feldom 



or never neceffary, and its nature may be deteded in the fame 



manner as that of the ftones or gravel. It is always either 



(iiicious fand, or calcareous land, or a mixture of both. U it 



confifts 



