AGRICULTURAL TEXT-BOOK. 27 



and ulmin are insoluble in alkalies and in water ; the others are readily 

 soluble in alkalies, and more or less in water also. 



89. All organic matter may be resolved into the four gasses, 

 carbon, oxygen, hydrogen, and nitrogen ; with or without a little 

 ash, or inorganic matter. 



90. The nature and quantity of organic matter in the soil have 

 great influence upon its character and fertility. 



91. The most useful portions of plants are chiefly organic; 

 as the woody fibre, starch, gum, sugar, gluten, and albumen ; 

 and in animals, the flesh, milk, butter, cheese, &c. Barn-yard 

 manures, are also chiefly composed of water and organic matter. 

 Thus, in well-preserved manure is found (Richardson,) in 100 

 parts : 



Water, - - - 65 parts. 



Organic matter, 24J- &quot; 



Inorganic salts, - - 10 



92. The inorganic matter forms the smallest portion of the 

 soil, but it is absolutely essential for the production of useful 

 vegetation. Without it plants will not produce seed ; and the 

 deficiency of a single element may render the soil entirely 

 barren. 



93. The names of these inorganic elements are: 



Nome. In combination with Forming 



Chlorine, (Bleaching Gas,) Metals, Chlorides. 



Iodine, - &quot; Iodides. 



Sulphur, - &quot; Sulphurets. 



- Hydrogen, Sulphuretted Hydrogen. 



&quot; - Oxygen, Sulphuric acid. 



Phosphorus, - &quot; Phosphoric acid. 



Potassium, - &quot; Potash. 



- Chlorine, Chloride of Potassium. 



Sodium, - Oxygen, Soda. 



- Chlorine, Common Salt. 



Calcium, - &quot; Chloride of Lime. 



