[ 468 ] 
methods of examining mineral waters may have 
been improved by the fagacity and induftry of later 
chemifts, it muft be owned, that we are Hill far 
from perfection in that point j and perhaps the mod: 
adtive parts of waters, on which their virtues chiefly 
depend, may lie fo much out of our reach, as not 
to be the objects of fenfe, or difcoverable by any 
experiments. Dr. Winter, in his Cyclus Metafyncri- 
ticus , has a very pertinent obfervation to this pur- 
pofe, which I cannot forbear transcribing. “ It is 
“ not neceflary, fays he, that waters fhould con- 
i( tain fo large a quantity of the particles they have 
u imbibed, as may be evident to our fenfes : for we 
<c know by experiment, that reg, antirnon. ffe- 
“ xprently macerated in wine, lofes nothing of 
“ its weight or fubftance, tho’ the wine proves 
<{ ftrongly emetic, p. 40.” And may not waters be 
impregnated fomewhat in the fame way by ef- 
fluvia from mineral fubflances unknown to us, and 
therefore not difcoverable by any experiments ? 
Worcefter, T. Wall. 
Dec. 12, 1755. J 
XL 1 V. 
