eit se! | 
which fwells up. into bubbles by the 
heat of the fun; and that. the cold 
of the night i is the reafon why thete 
air ‘bubbles do not make their ap 
pearance at that time. As he found 
that dry leaves put under water ga- 
_ther fuch bubbles alfo upon. their 
~farface, he concludes, p. 33, that 
the appearance of thefe bubbles can- 
not be owing to any vital action in 
the leaves. 
_I took fome pains to difel: fe the 
Cate of thefe bubbles, whieh, I 
ee are 2 of more i ortance th 
Shear to ve rit found the fact to 
be generally this: 
The moft part of leaves gather 
“thefe bubbles upon their furface, 
when plunged 1n apy water in the 
-fun-fhine or by. day-time in the 
open air; but infinitely more re =in 
ee 
