1 1 8 Vegetable Stanch. 



was much fap loft, the fap would fubfide in 

 the firft tube 5 but they would not afterwards 

 have their fap in Equilibrio 5 i. e. the furfacc 

 of the fap in each was at very unequal heights ; 

 the reafon of which is, becaufe of the diffi- 

 culty with which the fap pafles thro 5 the 

 almoft faturate and contracted Capillaries 

 of the firft cut ftem. 



In very hot weather many air bubbles 

 would rife, fo as to make a froth an inch 

 deep, on the top of the fap in the tube. 



I fixt a fmall air Pump to the top of a 

 long Tube, which had 12 feet height of fap 

 in it 5 when I pumped, great plenty of bub- 

 bles arofe, tho' the fap did not rife, but fall 

 a little, after I had done pumping. 



In Experiment 34. ( where a Tube was 

 fixed to a very Ihort ftump of a Vine, with- 

 out any lateral branches) we find the fap 

 rofe all day, and fafteft of all in the greateft 

 heat of the day: But by many obfervations 

 under the 37th and this 38th Experiments, 

 we find the fap in the tubes conftantly fub- 

 fided as the warmth came on towards the 

 middle of the day, and fafteft in the greateft 

 heat of the day. Whence we may reafon- 

 ably conclude, (considering the great per* 



fpira- 



