286 ESSAYS ann OBSERVATIONS 
lars: for, if the affertion of certain Chemifts 
was well founded, it would, ina great mea- 
fure, fuperfede any further inquiries. 
I. THE notion of an univerfal menfruum, 
capable to diflolve equally every body to 
which it is applied, appears repugnant to the 
nature of things, and to thefe limited powers 
which we difcover in all known bodies. 
I fhall not undertake, in this place, to ad- 
duce and examine the bold affertions and: 
high . pretenfions of fome Chemifts to the 
difcovery of an univerfal folvent ; becaufe 
it would exceed the limits which I propofe to 
myfelf, and perhaps afford little entertain- 
ment or inftruction. But I muft be allowed 
to doubt of the poffibility of an univerfal fol- 
vent, until more certain evidences are produ- 
ced than what have hitherto appeared. For, | 
as there is a vaft variety of bodies which dif- 
fer much from one another in denfity, foli- 
dity and texture, in the bulk, fhape and com- 
pofition of the conftituent particles, in the 
degree of force with which thefe cohere a- 
mong themfelves, and in the number, fize, 
and figure of the pores or interftices be- 
twixt the folid parts; it is {carce conceivable, 
that _ 
