VOL. XXXVIII.] I'HILOSOPHICAL TRANSACTIONS. 601 



have been to his purpose; but he found nothing like phosphorus, there coming 

 over only a bituminous oil; and at last, by increasing the fire to the highest 

 degree, there sublimed some white talcky flowers, which were neither sul- 

 phureous, nor acid, nor alcalic, but insipid like talc; so he gave up all further 

 experiments on other minerals. 



He has often wished for a sufRcient quantity of the flies which shine in the 

 dark, of which there are great numbers in Italy, especially in Tuscany; or of 

 our common glow-worms, which seem to have phosphorus lodged in their bodies. 



This phosphorus is a subject that occupies much the thoughts and fancies of 

 some alchymists, who work on microcosmical substances ; and out of it they 

 promise themselves golden mountains. Of this number was the famous Dr. 

 Dickinson, physician to king Charles 11: he toiled and laboured many years in 

 experiments on the stercus humanum; and has several times with the greatest 

 pleasure showed me metallic reguluses, he had extracted from it. This is what 

 Mr. H. had often done himself, and no wonder (he observes) for we take in 

 daily with our food, and sometimes in medicines, both mineral and metallic 

 substances, besides what metallic vessels, kettles, pots and dishes furnish: we 

 see a solution of the metal on a knife after cutting any acid fruit, by the black 

 spots on it, and the metallic taste it communicates to the thing it cuts. 



Dr. Lister has shown, that stones out of the human bladder being calcined, 

 iron may be extracted from them by a loadstone. And the great Boerhaave 

 has made it evident, by various experiments, that there is scarcely any ter- 

 restrial substance, either in men, brutes, or plants, which after union does not 

 exhibit some metallic particles. Dr. Becher says, that out of brick-earth mixed 

 with any fat or oil, and calcined in the fire, he has produced iron : for it is 

 only the iron that causes the redness of the bricks, and can be extracted from 

 them again. Moreover, metals are dissolved by the salts and moisture in the 

 earth, and so mix with the nutritious juices of vegetables ; hence it may in 

 some respect be said, that we eat metals with the greatest part of our food. 



Having given the foregoing short account of the production of phosphorus, 

 Mr. H. subjoins, that there is produced out of the residuum, after the phos- 

 phorus is made, a particular salt, which he names sal phosphori, or salt of 

 phosphorus. This salt is fixed in some degrees of fire; yet it may be sublimed 

 in a close vessel, which other fixed salts cannot be, except they still contain 

 somewhat volatile in them; but this salt has no such thing in it, neither is it 

 anywise alkaline. How to produce this salt, remains as much a secret as the 

 phosphorus itself; for he that cannot produce this salt, will never be able to 

 make phosphorus. 



There is scarcely any substance, out of which a chemical operator cannot pro- 



VOL. VII. 4 H 



