On the Analysis of Soils. 37 



Grains. 



Brought over - 270 



Of minutely divided matter separated by filtration^ 

 and con:?isting of 

 Carbonate of iiine - - 23 



Carbonate of magnesia - - 4 



Matter destructible by heat, principally ve- 

 getable, - ' - - 10 

 Silex _ - _ - 40 

 Alumine _ _ - - *33 

 Oxide of iron _ _ - 4 

 Soluble matter, principally sulphate of pot-» 



ash and vegetable extract, - 5 



Gypsum - _ - - 3 



Phosphate of lime - - 2 



125 



Amount of all the products 395 

 Loss - - 5 



in this instance the loss is supposed small ; bat in general, 

 in actual experiments, it will be found much greater, in 

 consequence of the difficulty of collecting the whole quan- 

 tities of the different precipitates; and when it is within 

 thirty for font- hundred grains, there is no reason to suspect 

 any want of due precision irithe processes. 



XV. This general Method of Analysis may in many Cases 

 be much simplified. 



When the experimenter is become acquainted with the 

 Use of the different instruments, the properties of the re- 

 agents, and the relations between the external and chemical 

 qualities of soils, he will seldom find it necessary to per- 

 form, in anv one case, all the processes that have been de- 

 scribed. When his soil, for instance, contains no notable 

 proportion of calcareous matter, the action of the nniriatic 

 acid IX. may be omitted. In examining peat soils, he 

 will principally have to atteni to the operation by fire and 

 air X. ; and in the analysis of chalks and loams, h^ will 

 often be able to omit the experiment bv sulphuric acid XI. 



In the first trials that are made by persons unacquainted 

 with chemistry, they must not expect much precision of 

 teiiiit. Many difficihies will l)e met wiih; bnl, in over- 

 coming them, the most useful kind of practical knowledge 

 will be obtained ; and nothnig is so iustnicLive in expen- 

 nicntal science as the detection of mistakes. The /::orrect 



, aualvst 



