PHYSICAL AND LITERARY. 323 



to be moft extenfive, are found incapable 

 of diflblving a great many other bo- 

 dies. 



II. The denfity, folidity, hardnefs, 

 fixednefs, and other manifeft qualities of 

 bodies, can afford us no certain mark or 

 indication of the qualities of the liquors 

 requiiite to diffolve them, if experience is 

 wanting. Neither can we conclude, from 

 the ftrength, ftiarpnefs, or corrofivenefs 

 of liquors, difcovered by their effects on 

 the human body, the fitnefs of fuch li- 

 quors to diffolve different fubftances. 



Iron and copper, the hardefl: of the 

 metals, which require the greateft force to 

 extend them, and the ftrongeft fire to 

 bring them to fufion, will be corroded and 

 diffolved by liquors moft harmlefs to the 

 tuman body ; as vinegar, juice of le- 

 mons, a folution of tartar, rhenifli wine, 

 nay, moift air : Whereas quick-filver, 

 whofe particles are fo mobile, eaiily fepara- 

 ble and diffipated by a moderate heat, and 

 tin, which is very foft and eafily melted, re- 

 quire more corrofive menftrua. Coral, and 

 fome of the hardeft gems, will be better 



diffolved 



