

': 



r 



. 



« - 



r 



e z 



Halle Stal'ids. 



1 



the tranfvcrfe cut of the branch, was co- 

 vered with innumerable little hemifphcrcs of 

 air, and many air bubbles iffucd out of 

 the fap veffcls, which air did in part fill 

 the tube e r, as the water was drawn out of 

 it; fo that the height of the mercury could 

 only be proportionable to the excels of the 

 quantity of water drawn off, above the quail 

 tity of air which iflued out of the wood. 



And if the quantity of air, which iflbed 

 from the wood into the tube, had been equal 

 to the quantity of water imbibed, then the 

 mercury would not rife at all ; becauie there 

 would be no room for it in the tube. 



But if 9 parrs in i z of the water be im- 

 bibed by the branch, and in the mean time 

 but 3 fuch parts of air iiliic into the tube, 

 then the mercury mult needs rife near <5 inches, 

 and fo proportionably in different cafes. 



I obferved in this, and moll of the follow- 

 ing experiments of this fort, that the mer- 

 cury rofe highclt, when the fun was very 

 clear and warm ; and towards evening it- 

 Would fubfide 3 or 4 inches, and rife again 

 the next day as it grew warm, but feldom 

 to the fame height it did at full. For I 

 have always found the fap vcffels grow every 



G -, day, 







1 



