160 ESSAYS 4nd OBSERVATIONS 
Jur la glace, edit. 1749 pag. 248. et eq. 
When I firft read the experiments of M, 
de Mairan in the place referred to, I fuf- 
pected that water, and perhaps other fluids, 
in evaporating, produced, or, as the 
phrafe is, generated fome degree of cold. 
The above experiment of my pupil confir- 
med my fufpicion, and engaged me to. 
verify it by a variety of new trials. 
I began by repeating the experiment 
with fpirit of wine; and found, when I 
had taken the utmoft care to have the {pi- 
rit exactly of the temperature of the air, 
that conftantly however, upon taking the 
thermometer out of the fpirit, the mer~ 
cury funk feveral degrees, and indeed con- 
tinued to fink fo long as the ball of the 
thermometer continued wet with the fpirit 
of wine. I found alfo, when the ball be- 
_ gan to dry, and the mercury to rife again 
in the ftem of the thermometer, that, if 
the ball was again dipped into the {pirit, 
and immediately taken out, the mercury - 
in the thermometer might be again obfer- 
ved to fink, and that thus, by repeated 
dippings, the cold produced might be ren- 
dered 
