( SI ) 
Dew in any Place. As firft, the Place in the Day* 
time mull be expofed to the Rays of the Sun for a 
confiderable time j for in fhady Places, or where 
the Sun Haines but little, little or no Dew is to be 
found. There tnuft alfo be a confiderable Difference 
between the Heat of the Day, and the Cool of the 
Night ; and in the laid Place a fufficient Moifture in 
the Earth. 
In treating of that Kind of Dew which is a Secre- 
tion or Exudation of a Juice in Vegetables, he ob- 
ferves, that fome Plants furnifh the Speftator with a 
very entertaining Sight, the little Drops of Dew being 
difpofed after a very regular, not fortuitous Man- 
ner, upon the Surfaces or Edges of their Leaves. 
He gives us the Figures of fome of them in a 
Plate. ■ 
To determine whether this beautiful Difpofition of 
the dewy Particles is owing to a Defcent from the 
chill’d Air over the Plant, or a Secretion made from 
the Juices of the Plant itfelf, he covered feveral 
with Glaffes, or earthen Velfels, having their 
Mouths downwards ; and yet the next Day plenty 
of this kind of Dew appeared in its ufual regular 
Form. 
As to the next Species, or common Dew, he pro- 
duces fo many, and fo differently made Experiments, 
again# the vulgar Opinion of its Defce nt that if 
they be all true, it feems difficult to fupport it a- 
gainft them. I fhall mention fome of the prin- 
cipal. 
For two Months together, viz. June and July in 
1718, every Night, feveral fmooth Plates of Brafs 
G z were 
