250 . Natural Hiftory of Pbofpborus. [Book VI. 



number of metallic fubftances, but readily diflblves, 

 in its fluid ftate, iron, zinc, and copper, with which it 

 forms falts not cryftallizable. 



Phofphorus feems to be almoft univerfal in the ani- 

 mal kingdom, and is alfo found in fome minerals, and 

 in a very minute proportion in mofl vegetables. The 

 bones of animals are a true phofphat of lime, or an 

 earthy fait compofed of phofphoric acid and calcareous 

 earth. The urine alfo contains a confiderable quan- 

 tity of phofphoric acid, chiefly combined with volatile 

 alkali, but partly alfo with calcareous earth. This 

 compound fair, afforded by the evaporation of urine, 

 was formerly known by the names of eilential fait of 

 urine, or microcofmic fait. Brandt, Kunkel, and 

 MargrafF, and all chemifts, till lately, prepared their 

 phofphorus from that fubftance, but it is now almoft 

 entirely obtained from bones, which afford it more 

 plentifully and with lefs trouble. Phofphorus does 

 not yet feem to have been applied to any important 

 tifts. 



From the remarkable eafe with which phofphorus 

 is inflamed, feveral experiments may be exhibited by 

 means of it, which appear like the effects of magic to 

 perfons unacquainted .with the nature of this fub- 

 ftance. Thus, for example, if the outfide of a bottle 

 is rubbed with phofphorus, and then furrounded with 

 tow, and hot water pourtd into ir, the phofphorus 

 takes fire, and communicates the inflammation to the 

 tow. If a flick of phofphorus is ufed to write on a 

 piece of paper, or en a wall, a quantity of phofphorus 

 is abraded, and, undergoing a flow combuftion, ren- 

 ders the ftrokes vifible in the dark, while in the 

 light they can only be perceived to exhale a whitifh 

 vapour. 



A fluid called liquid phofphorus is prepared by 



digefting 



