PHYSICAL AND LITERARY. 327 



that oleum vitrioli poured on quick filver, 

 and kept in the common air, or in a very 

 gentle heat, does not corrode or diflblve 

 it; but, if they are brought to a heat ex- 

 ceeding that of boiling water, then the fo" 

 iution takes place. Mr Boyle teftifies, 

 that, by his care to redtify or de- 

 phlegmatc aqua Jot lis very much, he ren- 

 dered it unfit to diflblve filver. While 

 aqua fortis is diflblving copper with a 

 brilk motion, if a little alcohol is poured 

 in, the folution will be flopt, 



V. So M E bodies, which we know can be 

 cafily diflblved in certain liquors, may be 

 fo changed by the fire, or other ways, that 

 the fame liquors will not afterwards dif- 

 folve them. On the other hand, the fire 

 renders fome bodies fit to be difTolved in 

 certain liquors which could not be difTol- 

 ved in them before. 



Th e oil of vitriol, as I faid before, af- 

 filled by a proper degree of heat, readily 

 enough diflblves quick-fiiver : But when 

 quick-filver is, by long digeflion in a mo- 

 derate heat, deprived, of its fluidity, and 



turned 



