434 Dr. ingen-hous'z on the Influence of the 
water is not renewed) is, that the water being at laft ex- 
hausted of its air can yield no more, it would neceSSarily 
follow, that the water, thus fuppofed to be deprived of air, 
Should be Similar to diddled or boiled water ; hut it is quite 
the reverfe. This very water, indead of being exhauded 
of air, gives evident Signs of being over Saturated with it. 
It fparkles almod as champaign does, when Shook by day- 
time in the fun ; and it will, when it is at that time feparated 
from the vegetable, yield by itfelf in the fun, but more fo by 
the fire, a good quantity of dephlogidicated air. The reafon 
why the green matter ceafes at lad to yield more air is therefore 
by no means becaufe the water is- exhaufted of air ; but, on 
the contrary, becaufe it is too much faturated with it, and that 
with an air hurtful to vegetable life, and becaufe this water 
has at laft loft its own natural air, and together with this air 
the nourishing and phlogistic particles which are neceflary to 
keep up the full vigour of plants. 
If it was the water, and not the vegetable, which furnifhed 
the dephlogiSlicated air, why Should the air bubbles not fettle 
indifferently on either furface of the leaves ? In this fuppofi- 
tion, how could that admirable- regularity be accounted for, by 
which all the leaves of a vine and a lime-tree are fird covered 
with air bubbles on the under lide, and all the leaves of 
lauro-cerafus , at the upper furface, whichever furface of the 
leaves is expofed to the rays of the fun ? Why Should 
the air always fettle on moll leaves in the form of bub- 
bles, but never fo upon the leaves of the tropteolnm majus , 
at lead during the fird hours, but always in the form of 
bags, adhering to the upper edge of the leaves, and de- 
taching themfelves when they are grown to a certain 
Size, 
