168 ESSAYS anp OBSERVATIONS 
fociety a proper account of them. In the 
mean time, I fhall give you the following 
facts already fufficiently verified. 
A thermometer hung in the receiver of 
an air pump, finks always two or three 
degrees upon the air’s being exhaufteds 
After a little time, the thermometer za va- 
cuo returns to the temperature of the air 
in the chamber, and, upon letting air a- 
gain into the receiver, the thermometer 
always rifes two or three degrees above the 
temperature of the external air. 
WHEN aveflel containing fpirit of wine, 
with a thermometer immerfed in it, is fet 
under the receiver of an air-pump ; upon 
exhaufting the air, the mercury in the 
thermometer finks feveral degrees. It be- 
comes miore efpecially remarkable when 
the air in any plenty iffues out of the fpi- 
rit of wine. As the {pirit continues long 
to give out air, fo it is long before the 
thermometer immerfed in it returns to the 
temperature of the external air. But when 
after fome time it appears {tationary, if it 
is then drawn up out of the fpirits and 
fufpended in. the vacuum, the mercury 
finks 
