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XIV. EXPERIMENTS 
RESPECTING DEW, INTENDED TO ASCERTAIN WHETHER DEW 
IS THE DESCENT OF VAPOUR DURING THE NIGHT,OR — 
THE PERSPIRATION OF THE EARTH, OR OF 
PLANTS ; OR WHETHER IT IS NOT THE 
EFFECT OF CONDENSATION. 
By NOAH WEBSTER, Esq. Ff. 4. a. 
at inde Sate 
IN the summer of 1790, 1 sank three pieces of pone equal 
weight; one I laid under a China saucer on the dry garden earth ; 
another was laid on the dry Berclen earth in the open air; the third 
was placed on green grass under cover. In the morning the paper, 
which lay under cover, was covered with dew, as well as that, which 
lay in open air ; and that, which was on dry earth, under the saucer, 
was a little the heaviest. The dew on all of them was mostly on the 
under side next the earth, and stood or rather hung in small globules. 
The surface of the earth was dry, but as the season was rainy, the 
earth just below the surface was moist. The result of these experi- 
ments was, to prove dew to be the perspiration of the earth. 
‘In July 1791 I made other experiments. The season was re- 
markably dry, and the earth at and near the surface retained very lit- 
tle moisture. I laid two China plates upon the dry surface of the 
earth, and in the morning found no dew on either of them. Yet the 
green vegetables about them were covered with a light dew. By this 
I judged, that the moisture of the earth was exhausted to such a depth, 
during the superior heat of the day, that no evaporation took place 
during the night, when the air was cooler. To satisfy myself in this 
