94 Vegetable Staticks. 



(as the warmth of the fun increafes upon it) 

 unlefs you fill the tube firft full of water: 

 For if half or | of the large tube cr be full 

 of air, that air will be rarefied by the fun; 

 which rarefa&ion will deprefs the water in 

 the tube, and confequently the mercury can- 

 not rife. 



But where little water is imbibed the firft 

 day, (as in the cafe of the green moots of the 

 Vine, Exper. XXIII.) then the mercury will 

 rife the fecond and third day, as the warmth 

 of the fun comes on, without refilling the 

 little water that was imbibed. 



Experiment XXV. 



In order to make the like experiment on 

 larger branches, (when I expected the mer- 

 cury would have rifen much higher than in 

 fmall ones) I caufed glaffes to be blown 

 of the fhape of this here defcribed (Fig. 12.) 

 of feveral dimenfions at r, from two to 

 five inches diameter, with a proportionably 

 large cavity c, the ftem z as near i. inch 

 diameter as could be, the length of the ftem 

 16 inches. 



I cemented one of thefe glafs veflels to 

 a large fmooth barked thriving branch of an 



Apple-. 



