Royal Society. 83 
Corollary i..,The air abounds in volatile falts, but that they 
muft be called nittous falts, has been fcarcely doubted of, tho' 
this experiment and fome others do contradi6l it 5 for nitrous 
falts feem not to have any property of volatile fait, nitre being of 
fo fixed a nature, that it will continue melted in a very llrong 
fire, with fcarce any evaporation 5 but if you put into it charcoal, 
or brimflone, or give it an accenfion, you may obtain a great 
quantity of fixed fait, fo that gold feems not to be of a more 
fixed nature. 
Cor. 1. A flandard of volatile falts fliould be fettled, and 
Dr. Slare could think of none better than water; that fait, which 
in diflilLition is more fixed than water, fliould not be reckoned 
amongft volatile falts j this flandard will be juftified by good 
meafures, grounded on experience 5 for all falts, that are truely 
volatile, are really lighter than water, that is, in a chemical fenfe, 
do with a lefs degreeof heat fublime in our glaffes, or come over 
the helm, than water does; this is juftified in the volatile fait of 
amber, erroneoufly fo called; for it does not come up to the 
ftandard of volatility, and is really no volatile filt, as will be 
made appear, if you take this fuppofed volatile fait, and diftil it 
in a retort, or head and body, with common water, the water 
will afcend in fuch a degree of fire, where the fait will not; for 
you muft encreale your fire confiderably, to make it rife after the 
water is evaporated, and left the dry fait at bottom ; this made 
the Dodor enquire farther into the pro})erties of this ialr, which 
did not at all correfpond with volatile lalts, (for all true volatile 
falts are alcali's) but on the contrary, would ferment with them, 
and quite deftroy the property of true volatile falts, by bringing 
them to a dull infipid fair, which fome call Sal Neutnm-^ and 
alio by fixing their volatile nature, quite deftroy their fpirituous 
and ftimulating Imell, by virtue of which, they have been always 
deiervedly efteemed fuch excellent cephalic medicines; therefore, 
examining this fait yet a little farther, you will plainly prove it 
to be an acid, that corrodes iron, turns fyrup of july-flowers 
green, deftroys the tincture of Lignum Nephritlam, and does 
not ferment with common acids; fb that it plainly belongs to the 
tribe of acids, and fliould be flruck out of the catalogue of vola- 
tile falts, and perhaps out of the number of fpecific cephalics, 
and rather be degraded amongft the diuretics, and even in that 
rank to have but "an inferior ftation; for it feems to be but a dull 
medicine, and more valuable for its price than great virtue, 
cfpecially, if quite diveiled of all its oil, in which the great 
cephalic and cordial virtues muft needs be owned to confift. 
L 2 Cor. 
