314 THE SOIL. 



of water, and add half a wine-glassful of muriatic acid ; 

 stir it thoroughly during the day, and let it stand and settle 

 over night. Pour off the clear liquid in the morning, and 

 again fill the vessel with water and stir thoroughly, and 

 when clear again pour it off; dry the soil and weigh it. 

 The loss is the quantity of lime the soil contained. If it 

 exceeds 5 grs., class as a marly soil ; if more than 20 grs., 

 class as a calcareous soil. 



9. VEGETABLE MOULDS, which are of various kinds, con- 

 taining from 15 to 60 or TO per cent, of organic matter. 



To analyze vegetable moulds, with a view to their classifi- 

 cation as above. 



E-ULE. Dry the soil well in an oven, and weigh it ; then 

 heat it to a dull redness, over a lamp or bright fire, until the 

 combustible matter is burned away and evaporated. Again 

 weigh it, and the loss is the quantity of organic matter it 

 contained. 



Besides the foregoing ingredients, every soil must contain 

 more or less of all the elements which enter into the com- 

 position of vegetation. They must hold, in a form adapted 

 to its growth and support, silex, alumina, carbonate of lime, 

 sulphate of lime, potash, soda, magnesia, sulphur, phos- 

 phorus, oxide of iron, manganese, chlorine, and, probably, 

 iodine. They are called the u inorganic or earthy parts of 

 soil," and constitute from one-half of one per cent, to over 

 ten per cent, of all vegetables. Their analysis is too diffi- 



