[ ^58 ] 
If we rub Hungary water, or any other volatile 
fpirit, over our hand, it will feel much colder than 
water, though they be both of the fame tempera- 
ture, and will both feel equally cold if we dip our 
finger into each. The reafon of which is, that the 
fpirit evaporating much quicker than the water, pro- 
duces thereby a greater degree of cold ; and fo 
aether, if it be applied in the fame way, will feel 
colder than any other fpirit on account of its more 
fudden evaporation. • 
Sixthly ; It is known that redtified fpirit of wine, 
when well purged of air, will imbibe a large bub- 
ble of air, in a much fliorter time, than water will 
do j and I have myfelf experienced the truth of this, 
which fhews that there is a ftronger attradlion or 
affinity,- as the chymifts call it, between fpirit of 
wine and air, than between water and air j and fince 
the fpirit evaporates much fafter than the water, I 
think we may conclude from hence, that the eva- 
poration of fluids arifes from an attradlive force be- 
tween their particles and thole of air *. 
* As water and fpirit of wine, are in no degree vifcid, they 
may evaporate in proportion to the attraftion between them and 
air. But the cafe is very different in fuch fluids as are vifcid ; 
for though I found that oil of olives, when purged of air, will 
imbibe a bubble of air almoft as foon as water does, yet the 
evaporation of the oil is hardly (if at all) fenfible in a very long 
time. The reafon of which muft be, that the attraction be- 
tween air and the oil, is not able to overcome the tenacity of 
its particles, and feparate them from each other, though it is 
fufficient to draw into the oil particles of air, which have no 
attraction to each other, juft as a fponge draws in water, with- 
out having its particles feparated by the attraction of the 
water. 
Seventhly ; 
