VOL. XXXVIIl.] PHILOSOPHICAL TRANSACTIONS. 597 



drs. that is 2 drs. more than the weight of the phosphorus before deflagration : 

 they were so very light, that they just filled a half pint pot.* 



The 10 drs. of flowers being set in a cool moist place, exposed to the air, 

 resolved into a liquamen, weighing 4 oz. 1 drs. which liquamen much re- 

 sembles Ol. Sulph. per campanam; but contains an acid salt, more fixed in 

 the fire than any other salt we know of in nature, and having many other pro- 

 perties peculiar to itself, which other acid salts have not. 



The phosphorus receives this fixed acid from the urine only; for the salt 

 of urine is so fixed, that on a live charcoal with a blow pipe, it plays and rolls 

 about like silver on the cupel. And whereas all other liquid acids evaporate 

 with ease, this, on the contrary, is so fixed, as to require a greater heat for its 

 evaporation than that which keeps lead in fusion ; and the phlogistic part, not- 

 withstanding its lightness, is so intimately and firmly connected with the rest 

 of its principles, as to sustain a degree of heat equal to that cf red hot iron; 

 during which heat the salt sparkles and emits flames very bright for a good 

 while; and this sparkling being over, it remains red hot in fusion, and perfectly 

 transparent ; and by greater heat may be vitrified, as will be shown hereafter. 



He put the abovementioned liquamen into a glass retort, which he set in a 

 balneum marinae, and distilled it to a strong inspissation. It yielded only an 

 insipid phlegm ; except that towards the last it came over a little impregnated 

 with the acid, but not sharper on the tongue than if it had been a mixture 

 of half an oz. of vinegar with 4 oz. of water. 



Then removing the retort with the inspissated liquor into a sand-furnace, he 

 increased the heat gradually, so as to make the sand and retort thoroughly red 

 hot, till at last the bottom of the retort was ready to melt; he then left it till 

 next day, when being perfectly cold, he broke the retort, and found a most 

 admirable white salt at the bottom, which was so united with the glass as not 

 to be separated from it; and some was spread all over the retort quite up to the 

 neck, and, as near as he could guess by view, it seemed to be as much in quan- 

 tity, could he have taken it out to weigh it, as the original phosphorus from 

 whence it was produced : its taste was very sharp and saline; but notwithstand- 

 ing its great fixity, in having endured a melting heat for several hours, it re 

 lented again in a moist air, and in a few days was entirely resolved into a 

 liquamen. 



The phosphorus, after its deflagration, leaves an almost fixed red earth, or 

 caput mortuum, behind it, as mentioned in Dr. Frobenius's experiment. 

 Though it might be imagined, that all the inflammable parts of the phosphorus 

 had been burnt off^ in the first deflagration, which seemed very violent, yet this 



* The white flowers here mentioned were phosphoric acid. 



