228 CONSERVATIVE ORGANS. [LECT. V. 



four times its weight of water, and when " the 

 " soil is broken down and the water cool, by 

 " agitating the parts together and suffering them 

 " to rest for a minute or two, and then pouring 

 " off the water with what it holds suspended in it. 

 " The repetition of this elutriation will at length 

 " free the sand from all the other substances, and 

 " that being thrown on a filter and weighed, the 

 " result will give the quantity of uncombined si- 

 " lex in the soil." The water of lixiviation must 

 be preserved, as it will be found to contain the 

 saline and soluble animal and vegetable matters, 

 if any exist in the soil. 



Calcareous matter is discovered by adding to 

 the portion finally deposited from the water of 

 lixiviation a quantity of muriatic acid " twice the 

 " weight of the earthly matter ; but diluted with 

 " double its volume of water :" an effervescence is 

 occasioned if lime, or any other calcareous sub- 

 stance, be present, and muriate of lime is formed ; 

 to separate which, and ascertain the quantity of 

 the lime, the whole should be thrown into distilled 

 water. The water dissolves the muriate of lime ; 

 and the solution separated by filtration being eva- 

 porated to a certain degree, carbonate of soda is 

 next to be added to precipitate the lime. The 

 weight of the precipitate, after it is washed and 

 dried, gives the quantity of calcareous matter 

 contained in the soil. If magnesia be present, it 



