SQS PHILOSOPHICAL TRANSACTIONS. [aNNO 1/33, 



red earth retains so much of an unctuous phlogistic, that being placed over a 

 red hot fire, it swells up, and keeps in fusion a great while, emitting flames 

 and flashes of light, as long as it is kept on the fire; but when cold again, if 

 exposed to a moist air, it relents and resolves as the flowers do: for the acid 

 salt of the urine adheres so strongly to it, that though it undergoes severa 

 strong ignitions, it will relent again as often, when set in the air. 



He took some of the white salt that stuck to the retort, and in order to try 

 the utmost degree of its fixity, he put some of it into a crucible, and gave 

 it a vitrifying heat, in which it remained some hours, but was not yet run to 

 glass, appearing only like a fixed white earth, as hard as stone, and shining as 

 if just ready to vitrify; yet it was so far fixed, as not to relent any more in 

 the air ; hafl no saline taste, nor was dissolvable in water. He therefore took 

 another portion of the same salt of phosphorus, which he kept a longer time 

 in the vitrifying heat, and he found it at last run into perfect glass. 



Thus we see what a wonderful subject phosphorus is ! and how surprising 

 is it that such an inflammable body, consisting of tlie unctuous and acid parts 

 of the urine, should thus become glass! 



The conclusion which he makes from this remarkable experiment is, that 

 here is a perfect transmutation of bodies ; the pliosphorus being transmuted 

 into a fine transparent glass, of a bluish green colour, coming nearer to the 

 hardness of a diamond than any other glass, and in the same quantity as the 

 phospiiorus at first used, which, without any addition, produces this glass, 

 ounce for ounce.* 



He further adds, that the crude phosphorus, without any deflagration, but 

 only cut very small, or scraped fine with a knife, and laid on a glass dish in 

 moist air, will in about a week resolve into a liquamen near 8 times its original 

 weight: which liquamen is the same in all respects as that which comes from 

 the sublimed flowers by deflagration, and may be vitrified likewise. In scraping 

 the phosphorus, great care is to be taken not to do it too hastily, lest by heat- 

 ing it, you set it on fire.-f- 



Reflections on these Experiments. — Respecting the nature of phosphorus, it 

 is Mr. H.'s opinion that it does not exist in animals by itself; but when formed 

 out of urine, by means of putrefiiction and fire, its principal contexture is 

 found to consist of a subtle acid, concentrated by the salt of urine, and of a 

 fat depurated oil. 



Phosphorus affords us so many wonderful phasnomena, that to explain them 

 all would take up a large treatise ; a perfect phosphorologia, being what would 

 exceed the limits of this short account. 



* It is now known that this so called glass of phosphorus, is phospiioric acid deprived of water. 

 t The liquamen here mentioned is in the modern chemical nomenclature, termed phosphorous acid. 



