Vegetable Statkksl 
Experiment XX. 
I provided me 6 ThermometerSy whofe 
ftems were of different lengths, viz- from 
1 8 inches to 4 feet. I graduated them all 
by one proportional fcale, beginning from 
the freezing point 5 which may well be 
fixed, as the utmoft boundary of vegetation 
on the fide of cold, where the work of ve- 
getation ceafes, the watry vehicle beginning 
then to condenfe and be fixed ; tho’ many 
trees, and fomc plants, as grafs, mofs, 
do furvivc it 5 yet they do not vegetate at 
that time. 
The greatefl: degree of heat, which I mark- 
ed on my Thermometer Sy was equal to that 
of water, when heated to the greateft de- 
gree, that I could bear ray hand in it, wirh_ 
out flirting it about. A degree of heat , 
which is the middle, between the freezing 
point, and the heat of boiling water, which 
being too great for vegetation, may there- 
fore be fixed, as the utmoft boundary of 
vegetation, on the warm fide j beyond which 
plants will rather fade than vegetate, fuch 
a degree of heat feparating and difperfing , 
inftcad 
