192 SOME USEFUL EXAMINATIONS MAT BE JIADE 



all points which practice alone can not explain, must 

 go to them. 



But some objectors continue, " It is an immense tax 

 on the farmer that he must have every soil analysed, 

 every manure thoroughly examined; these investiga- 

 tions are expensive, and are unattainable for this 

 reason, by the great majority of the community." This 

 is quite true, but it is no less true that the great ma- 

 jority will never require such minute analyses. If the 

 soils in a particular district are all formed from the 

 same rock, one or two careful analyses will suffice to 

 determine the general character of the whole. So 

 with manures; a few analyses of any particular kind 

 will settle its value, in whatever part of the country it 

 may be used. In cases where there is any thing par- 

 ticularly obscure or puzzling, in a soil or field, chemi- 

 cal analysis must be called upon to solve the question. 



In most situations, as knowledge of these subjects 

 increases, the intelligent farmer will daily become 

 more and more qualified to experiment himself, for 

 particular purposes, using manures of known compo- 

 sition: he may thus frequently arrive, unassisted, at 

 just and important conclusions. 



There are, moreover, some points upon which the 

 practical man may experiment, without becoming a 

 chemist, and without previous instruction. To a no- 

 tice of the more important among these, I shall devote 

 the remainder of this chapter. 



SECTION II. AN ACCOUNT OF SOME SIMPLE CHEMICAL 

 TESTS AND EXAMINATIONS. 



The classifying of soils by means of mechanical 

 processes, has already been explained in Chapter V., 

 and it is only necessary here to recal attention to it. 

 When an analysis of this kind is completed, the farmer 

 has no light thrown from it upon the chemical com- 



