Fegetahle Staticks. 7 
fquare feet; that is, equal to \ of the furface 
of the plant above ground. 
If, as above, twenty ounces of water, at 
a medium, perfpired in twelve hours day 
(4 e) 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 toots, is — 2286 
fquare inches,- (/. ^.) ttw is = 4 -tp this gives 
the depth of water imbibed by the whole 
furface of the roots mz,, 4-t part of an inch. 
And the furface of the plant above ground, 
being 5616 fquare inches, by which divid- 
ing the 34 cubick inches, viz^ = rW, 
this gives the depth perfpired by the whole 
furface of the plant above ground, viz. 
part of an inch. 
Hence, the velocity with which water 
enters the furface of the roots to fupply the 
cxpence of perfpiration, is to the velocity, 
with which the fap perfpires, as 165 : 67, 
or as -Jy : t-I-t, or nearly as 5 : 2. 
The area of the tranfverfe cut of the mid^ 
die of the Item is a fquare inch ; therefore 
the areas, on the furface of the leaves, the 
roots, and ftem, are 5616, 2286. i. 
The velocities, in the furface of the leaves, 
B 4 roots, 
