96 Mr. Webster's experiments respecting dew. 
being the same. I dug below the surface several inches, and turned | | 
up earth moderately moist, over which I placed a China fruit plate. 
It was ten o’ clock at night, when I did this ; yet in the morning the ~ 
under side of the plate was covered with dew, so that upon turning 
it up on one side, seven or eight drops of water fell from it. This 
served to confirm my opinion, that the reason why no dew appeared 
on the plates, laid on the dry surface in the former experiment, was, 
that the earth was so far exhausted by the extreme heat of the sun, 
that the heat of the night would not carry on e 
poration from a con- 
siderable depth ; but when moist earth was placed at the surface, the 
evaporation was copious. On the same night, [placed another plate — 
over a fresh leaf of .a plant, the earth below being dry. In the mor 
ning the dew was considerable upon the under. side of the plate, and 
it was visible upon the leaf, more especially on that part of it, which 
was a little removed from the earth. On that part of the leaf, which 
was in contact with the earth, the dew was scarcely visible. 1 was 
at a loss to determine from this experiment, whether the dew was per 
spired from the earth or the plant ; nor could I account for the appeare 
ance of more dew on that part of the leaf, which was a little raised 
from the earth, than on the other. I had acs seaman 
the under leaves of squashes, cucumbers, &c. were perfectly dry it 
the morning, when the upper leaves, which were open to the skyy — 5 
were covered with dew. And from repeated examinations I found, — 
that both sides of the leaf were alike, either dry, or moist with dew» 
When dew covered the upper side.of a leaf, it likewise covered the 
under side, and when one side was dry, so was the other, ‘This fact 
I believe to admit of few or no exceptions, and it deserves notice» ae 
For if dew is the perspiration of the earth, which some think probable, 
why should the under leaves next the earth be without dew, while 
the upper leaves at the distance of one or two feet from the earth are 
