C 1 7° ] 
And here it is to be remarked, notwithdanding the 
contrary has been given out by fome, that thefe chy- 
mical oils mixed with the mod highly rectified fpirit 
of wine, do produce no cold, either upon their mix- 
ture, or half an hour after. 
It refults from thefe experiments, that although 
there are many liquids, which can produce artificial 
cold, the nitrous acid is the mod powerful j and 
mercury may be congealed by it, without any dif- 
ficult procefs, at any time, when the heat of the at- 
mofphere is not greater than 175 by the thermome- 
ter before-mentioned. And thefe experiments hav$ 
not only fucceeded with our author, but with many 
others ; among whom, it may be futficient to men- 
tion Mefiieurs Lomonofow, Zeiher, Aepinus, and 
Model, as thefe gentlemen have made themfelves 
well known in the philofophical world. The nitrous 
acid was poured upon the fnow, in no determinate 
quantity 5 fometimes a few drops were fufficicnt, 
fometimes it required a larger quantity. Snow feems 
to be more fit for thofe experiments, than pounded 
ice ; as the former, from its loofe texture, is of more 
apt and eafy folution. 
Hence it appears, that mercury is no longer to be 
ranked with the femi-metals, but as a perfect one, 
fufible, though with a much lefs degree of heat than 
any of the others. It agrees likewife with other 
metals ; as their parts like it, when in fufion, attract 
one another, and run into globules, and, from a date 
of fluidity, pafs into a folid date, not all at once, but 
fuccefiively, and vice verfa. But it is worth inquiring, 
whether this metal, which agrees with all others, 
both in a folid and fluid date, has not the particular 
5 property 
