132 EXPERIMENTS on EVAPORATION. 
2. The fecond tumbler which was inverted over the ice 
continued perfe€tly free from any moiflure or froft, al- 
though the firft was lined with it. 
3. [f one of the razors when placed in the cold veflel, 
was encrufted with a fmal! quantity of ice or moifture, this 
moifture would foon difappear, but if it was in large quan- 
tity, a part only would difappear, and the remainder con- 
tinue unchanged, although the razor was kept a long time 
in the cold veffel. 
Now it is probable that in the firft and fecond of thefe 
inftances, the evaporation commenced as foon as the heat 
began to flow from the ice to the air, and ceafed as foon 
as the ice was reduced to the temperature of the air, or as 
foon as the motion of the heat ceafed. 
The fame | believe happened to the ice on the razor, but 
the razor being a fmall body could have contained but little 
heat, of courfe therefore the evaporation from it muft have 
ceafed before much ice could have been removed. 
I cannot think of any principle upon which we can ac- 
count for the evaporation going on rapidly at one time, 
and ceafing at another, except this motion of heat, and 
there are fome other faéts of confiderable importance which 
may be explained by it equally well. Within the Polar 
regions, when the cold is very intenfe, a fmoke arifes from 
the fea which is warmer than the air of the land; Crantz 
the Moravian miffionary to Greenland, after defcribing the 
effets of the violent cold, adds, that ** at.thistime the fea 
reeks like an oven,” and that this {moke is diftinguifhed 
by the inhabitants by the name of frof /moke. As the 
circumflances attending this fmoking are fo fimiliar to 
thofe which attend the {moking ice, in the veffel, there is 
reafon to believe that they depend upon the:fame caufe. 
This explanation may alfo be rendered more probable, 
if it can be made to appear. that a procefs the reverfe of 
evaporation, depends upon a principle the reverfe of that 
we 
