Vegetable Statkhs. 7 



to 0.4. of the farface of the plant above 

 ground. 



If, as above, twenty ounces of water, at 

 a medium, perfpired in twelve hours day, 

 iV. c.) thirty-four cubick inches of water, (a 

 cubick inch of water weighing 254 grains) 

 then the thirty-four cubick inches divided 

 by the furface of all the roots, is = 2286 

 fquare inches ; (/. e.) -gfa is = fa this gives 

 the depth of water imbibed by the whole 

 furface of the roots, viz £j part of an 

 inch. 



And the furface of the plant above ground 

 being 5616 fquare inches, by which divide- 

 ing the 34 cubick inches, viz. s ffi 6 = y^-, 

 this gives the depth perfpired by the whole 

 furface of the plant above ground, viz. 7^-. 

 part of an inch. 



Hence, the velocity with which water 

 enters the furface of the roots to fupply the 

 expence of perfpiration, is to the velocity, 

 with which their fap perfpires, as 165 : 6j y 

 or as $f : ,|- 7 , or nearly as 5 : 2. 



The area of the tranfverfe cut of the mid- 

 dle of the ftem is a fquare inch ; therefore 

 the areas, on the furface of the leaves, the 

 rpots and ftem, are 5616, 2276. j. 



B 4 The 



