











* 



1 44 Vegetable Staticks. 



of wood confifts in the fhooting of their fi. 

 bres lengthways under the bark. 

 • That the fap does not defcend between the 

 bark and the wood , as the favourers of a cir- 

 culation fuppofe, feems evident from hence 

 viz. that if the bark be taken off for 3 or 

 4 inches breadth quite round, the bleeding of 

 the tree above that bared place will much 

 abate, which ought to have the contrary 

 efFect, by intercepting the courfe of the re- 

 fluent fap, if the fap defcended by the bark. 



But the reafon of the abatement of the 

 bleeding in this cafe may well be account- 

 ed for, from the manifeft proof we have 

 in thele Experiments, that the fap is ftrong- 

 ly attracted upwards by the vigorous opera- 

 tion of the pcrfpiring leaves, and attracting 

 Capillaries : But when the bark is cut off 

 for fome breadth below the bleeding place, 

 then the fap, which is between the bark and 

 the wood below that disbarked place, is 

 deprived of the ftrong attracting power of 

 the leaves, &c. and confequently the bleed- 

 ing wound cannot be fupplied fo faft with 

 fap , as it was before the bark was taken off. 



Hence alfo we have a hint for a probable 



conjecture why in the alternately disbarked 



{ticks, 



..'■: 









