j i Vegetable Stanch. 
Now fuppofingthe roots of the Sunflower 
(the longeft of which reached 1 5 inches eve- 
ry way from the ftem) to occupy and draw 
nourifhment from 4 cubick feet of earth, 
and fuppofe each cubick foot of earth to 
afford 7 pounds of moifture, before it be 
too dry for vegetation > the Plant imbibing 
and perfpiring 22 ounces every 24 hours, 
that will be 28 pounds of water, which will 
be drawn off in 21 days and 6 hours 5 after 
which the Plant would perifh if there were 
not freCh fupplies to thefe 4 cubick feet of 
earth, either from dew or moifture arifing 
from below 15 inches (the depth of the 
roots) up into the earth occupied by the 
roots. 
Experiment XIX. 
In order to find out the quantity of T)ew 
that fell in the night, Aug. 1 5* at 7. p. m. I 
chofe two glazed earthen Pans, which were 
3 inches deep, and 12 inches diameter in 
furface 3 I filled them with pretty moift earth 
taken off the furface of the earth. I fet 
thefe Pans in other broader Pans, to pre- 
vent any moifture from the earth flicking 
to the bottoms of them. The moifter the 
earth, the more Dew there falls on it in a 
night. 
