218 INORGANIC AGENTS 



SECTION VIII. 

 Phosphorus. 



Phosphorus. Phosphorus. P. (U. S. & B. P.) 



Derivation. —Digest bones in sulphuric acid, or treat 

 bone ash with sulphuric acid ; filter and evaporate. Ca, 

 (POJ, (bone ash) + 2 H,S O, = Ca H, (POJ, (acid calcium 

 phosphate) + 2 Ca So^. 



Heat acid calcium phosphate, charcoal, and sand to- 

 gether, and distil over phosphorus into water. 



Heat breaks up Ca H^lPO^^j into Ca (POJj (calcium 

 metaphosphate) + 2 HjO. 



Then : 2 Ca (PO3), + 2 SiO, + 10 C = P, + 2 Ca Si O, 

 -h 10 C O. 



Properties. — A translucent, nearly colorless solid, of a 

 waxy lustre, having at ordinary temperature about the con- 

 sistency of bees' wax. By long keeping, the surface becomes 

 red and occasionally black. It has a distinctive but dis- 

 agreeable odor and taste. It should not be tasted except in 

 a state of great dilution. When exposed to the air it emits 

 white fumes which are luminous in the dark, and have an 

 odor somewhat resembling garlic. On long exposure to the 

 air, it takes fire spontaneously. Insoluble in water, or 

 nearly so ; soluble in 350 parts of alcohol, in 80 parts of ether, 

 in about 50 parts of any fatty oil, and very soluble in chloro- 

 form and carbon disulphide. Besides the official form there 

 are several other allotropic forms of phosphorus, including 

 the red, or amorphous, the black, and the crystallized 

 metallic phosphorus. 



Red phosphorus is non-poisonous, and although it has 

 been commonly taught that it is inert, some recent experi- 

 ments have tended to show that its therapeutic value is 

 equal to that of the yellow phosphorus. 



Dose.—K., gr.i.-ii. (.06-.12) ; C, gr.ii.-iii. (.12-.18) ; Sh. & 

 Sw., gr-xi o-A (.0006-003); D., gr.-^-^ (.0006-.003). 



