VEGETABLE GROWING. 



be classified according to the amount of it they con- 

 tain. Under this classification we are acquainted with 

 the following divisions : 



1. Pure clay, from which no sand can be removed 



by washing. 



2. Strong clay, from which as much as 5 to 20 per 



cent, of sand can be separated. 



3. Clay loam, when washing will remove 20 to 40 



per cent, of sand. 



4. Loam, when the land contains as much as 40 to 



70 per cent, of sand. 



5. Sandy loam, from which 70 to 90 per cent, of 



sand can be separated. 



6. Light sand, containing more than 90 per cent, of 



sand. 



When soil is found to contain a per cent, of carbo- 

 nate of lime it is said to be calcareous or marly soil. 



When a large per cent, of vegetable matter is pres- 

 ent it is usually called muck or vegetable mold. 



COMPOSITION OF THE SOILS. 



Soils that are in good condition for raising crops 

 are made up of fourteen or fifteen elements. In all, 

 there are nearly seventy elements that may occur ; 

 but as only about fifteen of these enter into the ques- 

 tion of plant economy, we need not regard the other 

 fifty-five. 



ELEMENTS NECESSARY TO PLANT-GROWTH. 



The essential elements are oxygen, hydrogen, nitro- 

 gen, potassium, carbon, silicon, sulphur, phosphorus, 

 chlorin, sodium, calcium, magnesium, aluminum and 

 iron. Oxygen, hydrogen, nitrogen and carbon are 

 derived directly from the air and constitute 95 per 

 cent, to 99 per cent, of the weight of the plants. 

 While these four elements are derived from the air, it 



