yt z Mr. cavallo’s Account of 
fh all briefly relate fome obfervations made on the cold produced* 
by the evaporation of other fluids bolides ether. 
In a room, the temperature of which was 64° according to- 
Fahrenheit’s thermometer, and in which the air was gently 
ventilated, I obicrved the effects produced by various fluids 
when thrown upon the ball of a thermometer- The ball of 
this thermometer was quite detached from the ivory piece upon 
which the fcale was engraved. The various fluids were thrown 
upon the thermometer through the capillary aperture of a- 
{mail glafs veffel, fhaped like a funnel, and care was taken to 
throw them fo? (lowly upon the bulb of the thermometer,, that 
a drop might now and then fall from the under part of it ; ex- 
cept when thofe fluids were ufed, which evaporate very (lowly,, 
in which cafe it was fuflicient to keep the ball of the thermo- 
meter only moift, without any drop falling from it. During 
the experiment the thermometer was kept turning very gently 
round its axis, in order that the fluid ufed might fall upon every 
part of its bulb. This method I And to anlwer much better 
than that of dipping the ball of the thermometer into the fluid:; 
and removing it immediately after, or that of wetting the ther- 
mometer with a feather. The evaporation, and coniequently 
the cold produced by it, may be increafed by ventilation, viz*. 
by blowing with a pai-r of bellows- upon the thermometer ; but 
this was not ufed in the following experiments, becaufe it is 
not eaflly performed by one perfcn, and alfo becaufe it, occafion s 
very uncertain refults. 
With the above defcribed method I began to examine the 
effects of water, and found, that the thermometer was brought 
down to 56°, viz. 8° below the temperature of the room in. 
which the experiment was made, and of the water employed.. 
This 
