This process is the one usually employed by 

 chemical philosophers for the analysis of stones. 



8. If any saline matter, or soluble vegetable or 

 animal matter is suspected in the soil, it will be found 

 in the water of lixiviation used for separating the 

 sand. 



This water must be evaporated to dryness in a 

 proper dish, at a heat below its boiling point. 



If the solid matter obtained is of a brown colour 

 and inflammable, it may be considered as partly vege- 

 table extract. If its smell, when exposed to heat, be 

 like that of burnt feathers, it contains animal or albu- 

 minous matter; if it be white, crystalline, and not 

 destructible by heat, it may be considered as principal- 

 ly saline matter ; the nature of which may be known 

 by the tests described page 103. 



9. Should sulphate or phosphate of lime be sus- 

 pected in the entire soil, the detection of them re- 

 quires a particular process upon it. A given weight 

 of it, for instance four hundred grains, must be heat- 

 ed red for half an hour in a crucible, mixed with one- 

 third of powdered charcoal. The mixture must be 

 boiled for a quarter of an hour, in half a pint of water, 

 and the fluid collected through the fiitre, and exposed 

 for some days to the atmosphere in an open vessel. 

 If any notable quantity of sulphate of lime (gypsum) 

 existed in the soil, a white precipitate will gradually 

 form in the fluid, and the weight of it will indicate the 

 proportion. 



Phosphate of lime, if any exist, may be separated 

 from the soil after the process for gypsum. Muriaticr 



