PHYSICAL AND LITERARY. 321 



That liquor which makes the fepa- 

 l^afion of parts, I call the jolvent\ or, iri' 

 the ftile of the chemilh, the menfiruum. 

 ' t muft take the liberty to make one 

 jirelimiriary remark, before I defcend to 

 particillars: For, if theailertion of certain 

 clvemifts was well founded, it would, in 

 a great meafure, fupcrfede any farther ill-' 

 quiries. 



I, The notion of an unlverfal meriftr'ii-^ 

 um, capaBle to diifolve equally every bo-' 

 dy to which it is applied, appears repug- 

 nant to the nature of things, and to thefe- 

 limited powers which we difcover in all 

 known bodies. 



I Ihall not undertake, in tliis place, to" 

 adduce and examine the bold affertions'^ 

 and high preteniions of foxe chemifts' 

 to the difcovery of an unlverfal folvent; 

 becaufe it would exceed the limits which 

 I propofe tomyfelf, and p'erKaps aJfford'Iit-" 

 tie entertainment or inftruaioii.' But t'tiiii?!' 

 be allowed' to doubt of the poiTibility 6f 

 an univerfal' folvent, until more cercaiti 

 evidences are produced than what' lia-ver 



"^OL. I. Sf hitherto 



