( 140 ) 



After this, I put camphire in the water containing thefe falts, 

 but I tlid not perceive them mix with the water, though the cam- 

 phire llood in it for two days. 



I afterwards poured otF the water and poured fpirits of wine 

 on the falts, but I did not perceive them unite with the fpirits of 

 wine. 



In all my obfervations, I never faw any of the faline particles 

 in fhape like the figures of our common fait, and I will venture to 

 fay, that the fait which we commonly ufe \\ith our food, cannot 

 produce any addition to the Stone in the Bladder, unlefs it could 

 be proved, that fuch fait can be converted into a liony fubilance 

 in the body. But 1 know that many may not give credit to this, 

 and alledge, that though the Stones in the Bladder may, in part, 

 conlilt of common fait, yet by applying fire to them in the way I 

 have mentioned, they might aflume the different figures I have 

 defcribed to be in the volatile and fixed falts extracted from thence. 

 In order, therefore, to fatisfy myfelf and others in this refped, I 

 took fome common fait and put it into a new glafs, to which I 

 applied fo llrong a fire, that the glafs became red hot, and the fait 

 difiblved into water : when the glafs became cool, I broke it, and 

 taking out the fait, I mixed it with fair rain water, and then ob- 

 ferving it, I inw in the fpace of half a minute, nothing floating in 

 the water, except particles of common fait, but none like the fixed 

 or volatile fait extraAed from the Stone in the Bladder : when 

 this burnt lalt had fiood for fome hours, it was changed (the air 

 being then moitl) into a watery liquor, and upon applying fome 

 heat to it, nothing appeared except figures of common fait. 



And fince we fee that Stones taken out of the Bladder do in part 

 confift of fuch a fixed fait as is produced by infufing the burnt mat- 

 ter in water, and which feems for a time to unite with the water, 

 but foon afterwards coagulates, and becomes fo hard, that though 

 the water is boiled, this fait will not mix with the water ; and 

 ^Ifo tliat by fpirits of wine or camphire it cannot be difiblved ; 



