BV THE PRACTICAL FARMER 103 



position of his soil, except so far as the silica and 

 alumina, that is, the sand and clay, are separated, and 

 their proportions known. 



The following course may be adopted, in case more 

 information is desired, regarding the especial consti- 

 tuents of a soil. 



1. Take a weighed half pound or pound of the 

 soil, and boil it in water for some hours: rain water is 

 purest. Then pour it upon a filter of coarse porous 

 paper, of the kind that druggists use for their nitra- 

 tions. The mode of managing this operation, may be 

 seen in any druggist's shop. If the liquid does not 

 come through clear at first, it must be refiltered till it 

 is quite clear. The solution thus obtained is evapo- 

 rated to dryness, and the solid residue burned. It will 

 blacken at first, by the burning of its organic matter, 

 but afterwards will become white again. 



a. It may now be weighed on a small apothecaries' 

 balance, and the weight gives the percentage of in- 

 organic matter soluble in water, that exists in the 

 soil. 



b. This portion consists in many soils, for the most 

 part, of sulphates, or carbonates, of potash and soda. 

 There is also commonly present some chloride of jo 

 dium, or common salt. 



These are all valuable constituents of a soil; and 

 hence, where an experiment of this kind shows such 

 soluble matter to abound, it may be inferred that the 

 soil is well supplied with an important portion of its 

 requisite substances. 



c. The part soluble in water is commonly no* 

 large : it amounts to not more than from one to three 

 per cent, in many excellent soils. 



2. Take another weighed portion of soil, or the 

 same which has already been boiled in water, and 

 heat it with some muriatic acid (hydrochloric acid), 

 diluted by two or three times its bulk of water. After 



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