Vegetable Staticks. 9 



reafon of the reciprocal proportion) that 34 

 cubick inches may pafs the ftera in twelve 

 hours 5 whence its velocity in the ftem will 

 be 45 -j inches in twelve hours, fuppofing 

 there be no circulation, nor return of the 

 fap downwards. 



If there be added to 34, (which is the lead 

 velocity) -j of it = 1 1 §, this gives the greateft 

 velocity, viz. 457. The fpaces being as 3 : 4. 

 the velocities will be 4 : 3 : : 45 1: 34. 



But if we fuppofe the pores in the iurface 

 of the leaves to bear the fame proportion, 

 as the area of the fap-veffels in the ftem do 

 to the area of the ftem ; then the velocity, 

 both in the leaves, root and ftem, will be 

 increafed in the fame proportion. 



A pretty exact account having been taken, 

 of the weight, fize, and furface of this 

 plant, and of the quantities it has imbibed 

 and perfpired, it may not be improper here, 

 to enter into a comparifon, of what is taken 

 in and perfpired by a human body, and this 

 plant. 



The weight of a well-fized man is equal 

 to 160 pounds: The weight of the Sun- 

 flower is 3 pounds ; fo their weights are to 

 each other as 160: 3, or ^53: 1. 



The 



