C 365 ] 
which agree in one common folvent, the mephitic 
air, but differ from each other, according to the 
nature of the bafe to which this air is united. 
The agreement of thefe faline concretes with neu- 
tral falts in thefe effential properties, by which thefe 
laft are diftinguifhed from other more fimple faline 
bodies, will further appear from their decompofition ; 
which is effected by thofe various ways, and under 
the fame laws, by which all other neutral falts are 
decompounded 3 namely, by all thofe different ways, 
by which the acid fpirits, and the terrene or alcaline 
bafes of neutral falts, can be feparated from each 
other. 
For, firfi, the aereal fpirit of thefe faline concretes 
is forced, by fire , from its union with the earthy bafe, 
which it holds diffolved in water, in like manner as 
the acid fpirit of other neutral falts are expelled by 
fire from the more fixed principles, which enter the. 
composition of thofe falts.. The degree of heat re- 
quired to feparate the acid fpirit of neutral falts, from 
their more fixed alcaline or earthy bafe, varies in the 
decompofition of almofl every different kind of falts ; 
and the extreme volatility and expanfive force of this, 
aereo-faline principle renders it more ealily feparable,. 
by heat, from the fixed principles to which it unites, 
than any other kind of laline fpirit. 
Secondly. The faline concretes, formed with this 
aereal folvent (in like manner as other neutral falts), are 
decompounded by the addition oj flronger acids , which 
more powerfully attraft the terrene or metallic bafe of 
thefe concretes, than it is attracted by their light and 
fubtle aereal fpirit, and detaches from them the aereal 
folvent to which thofe earths were before united. All 
acids* 
