CHAPTER X 



PHOSPHORUS 



(Phosphorus = P) 



Introduction. Phosphorus is not found in the free 

 state in nature, but in compounds, in small quantities 

 rather widely distributed. It is a part of all living- 

 matter and is found in all fertile soils, as plants can 

 not grow without phosphorus. Large deposits of 'min- 

 erals are found containing phosphates, which are 

 extensively mined for use as fertilizers. Bone consists 

 of 80% of calcium phosphate, which, together with the 

 phosphates found in large mineral deposits, form the 

 chief sources of commercial phosphorus. 



Preparation. In obtaining phosphorus from bones 

 the combustible matter is burned out, leaving bone-ash 

 behind. 



Bone-ash or a pure mineral phosphate is then heated 

 with sand and carbon in an electric furnace. In the 

 heating, phosphorus vapor escapes through tubes and 

 is led under water where it condenses in molds. 



Properties. Yellow phosphorus in the pure state is 

 a translucent, waxy solid which when exposed to light 

 takes on a coating of darker color. If a piece of yelloAv 

 phosphorus is exposed to the air, it will begin to give 



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