THE ELEMENTS THAT PLANTS USE 57 



gen is the most abundant solid constituent of our globe, 

 and in less proportion is an equal necessary ingredient 

 of the Vegetable Kingdom, while in the Animal Kingdom 

 it occurs usually in mere traces. As sand just common 

 sand it is of the utmost value in making the soil a pleas- 

 ant and comfortable home for plants. 



Sulphur: the match maker. This element, while es- 

 sential to plant growth, is used only slightly as a con- 

 stituent of the albuminous bodies. At any ordinary tem- 

 perature it exists in nature as a solid, brittle and tasteless 

 body of a characteristic yellow color, and insoluble in 

 water. 



Sulphur is present in the soil sufficiently to supply all 

 the needs required of it by plants. It is extensively em- 

 ployed in the arts and manufactures, gunpowder and 

 sulphur matches being common forms of its use. 



Phosphorus : our most inflammable element. So readi- 

 ly does phosphorus burn, even at ordinary temperature, 

 it is necessary to keep it under water for preservation. 

 Because of its inflammable nature, it is successfully used 

 for the making of matches. 



Phosphorus is colorless or slightly yellow, translucent, 

 and poisonous. It occurs in nature in the form of phos- 

 phates or salts of phosphoric acid. Without it in the soil, 

 plants will not grow, for it is indispensable in the life 

 process of both plants and animals. 



The following may be mentioned as common forms of 

 its combination : 



1. With calcium and oxygen when calcium phosphate 

 is formed. 



2. With magnesium and oxygen when magnesium 

 phosphate is formed. 



3. With aluminum and oxygen when aluminum phos- 

 phate is formed. 



