l/egetahle Staticks. 85 
tity of thofe air bubbles thus fucked our, 
was but fmall ; yet in this and many other 
experiments, I found that after fuch luc- 
tion, the water was imbibed by the branch, 
much more greedily, and in much greater 
quantity than the bulk of the air was, which 
was fucked out. Probably therefore, thefc 
air bubbles, when in the fap velTels, do ftop 
the free afeent of the water, as is the cafe 
of little portions of air got between the wa- 
ter in capillary glafs tubes. 
When the mercury is raifed to its greateft 
height, by precedent fudion with the 
mouth, ( which height it reaches fometimes 
in 7 minutes, fometimes in half an hour or 
an hour) then from that time it begins to 
fall, and continues fo to do, till it is fallen 
5 or 6 inches, the height the branch would 
have drawn it to, without fucking with the 
mouth. 
But when in a very warm day, the mer- 
cury is drawn up 5 or 6 inches, ( without 
precedent fudion with the mouth ) then it 
will ufually hold up to that height for fe- 
veral hours, during the vigorous warmth 
of the fun > becaufc the fun is all that time 
ftrongly exhaling moifturc from the branch 
G 5 thro* 
