I I 



f/egetabk Stattch. 



*57 



for the fine capillary veffels to exert their 

 vaftly attraaing power, which pcrfpiration 

 is erTeded by the brisk rarifying vibrations 

 of warmth : A power that does not fcem 

 to be any ways well adapted, to make the 

 fap defcend from the tops of vegetables by 

 different veffels to the root. 



If the fap circulated, it mud needs have 

 been feen defcending from the upper part 

 of large games, cut in branches, fet in wa- 

 ter, and with columns of water preffing on 

 their bottoms in long glafs tubes, in Exp. 43, 

 and 44. In both which cafes, it is certain 

 that great quantities of water palled thro* 

 the ftem, fo that it muft needs have been 

 feen defcending, if the return of the fap 

 downwards were by trufion or pulfion, 

 whereby the blood in animals is returned 

 thro' the veins to the heart: And that pul- 

 fion, if there were any, mult necelTarily be 

 exerted with prodigious force, to be able 

 to drive the fap thro' the finer capillaries. 

 So that if there be a return of the fap down- 

 wards, it muft be by attraction, and that 

 a very powerful one, as we may fee by many 

 of thefc Experiments, and particularly by 

 Experiment 1 1 . But it is hard to conceive, 



what 









