fame 'Thermoinetrical h,xpentncnt$ „ 5 ; 3 
'This effedt was produced in about two minutes time* after 
which a larger continuation did not bring the mercury lower. 
By means of fpirit of wine the thermometer was brought 
down to 48°, which is only 16" below the tempeiatutc or the 
room, and or the fpirit employed. When the fpirit of wine 
is highly rectified, the cold produced by its evaporation is cer- 
tainly greater than when it is of the common loit ; but the dif- 
ference is not fo great as one, who never tried the experiment, 
might expedf. The purer (pint produces the effect much 
■quicker. 
Ufiirg various other fluids, which were either compounds of 
water and fpiritous fubflances, or pure efiences, I found that 
the cold produced by their evaporation was generally in lome 
intermediate degree between the cold produced by the water and 
that produced by the fpirit of wine. 
Spirit of turpentine brought the thermometer only 3 lowei 
than the temperature of the room ;, but olive oil and other oils, 
which evaporate either very (lowly or not at all, did not fenfl- 
bly afredt the thermometer. 
Willing to obferve how much electrization could mcreafe the 
evaporation of fpirit of wine, and eonfequently the cold pio- 
duced by it, I put the tube containing the fpirit into an in fil- 
iating handle, and connected it with the conductor of an elec- 
trical machine, which was kept in action whilft the experiment 
was performed ; by thefe means the thermometer was hi ought 
down to 47°. Having tried the three mineral acids I found, 
that inflead of cooling they heated the thermometer, which effect 
1 expeCted ; fince it is well known, that thofe acids atti act 
the water from the atmofphere, and that heat is produced 
by the combination of water and any of them. The vitri- 
die acid, which was very ftrong and transparent, 1 ailed the 
X x x 2 ' thermo- 
