on the Production of Dephlogifticated dir. \ j ^ 
appear, by all the experiments which have hitherto been made, 
to furnifh air only Jor a fleort time ; after a day or two, the 
leaves changing colour, ceafe to yield air : and this has been 
conceived to arife from the powers of vegetation being de- 
ftroyed ; or, in other words, the death of the plant ; and from 
hence it has been inferred, with fome degree of plaufibility, 
not only that the leaves adtually retained their vegetative powers 
for fome time after they were feparated from their flock, but 
that it was in confequence of the exertion of thefe powers, 
that the air, yielded in the experiment, was produced. 
But 1 have found, that though the leaves, expofed in water 
to the action of light, actually do ceafe to furnifh air, after a 
certain time, yet that they regain this power after a fhort in- 
terval, when they furnifh (or rather caufe the water to furnifh) 
more and better air than at firft, which can hardly be accounted 
for upon the fuppofition that the air is elaborated in the veffels- 
of the plant. 
Experiment N° zy. 
A globe, containing 46 cubic inches, filled with frefh fpring 
water and two peach leaves, was expofed in the window to the 
adtion of the fun’s rays, 10 days lucceflively (the weather 
being in general fine), when the following appearances took, 
place. 
The 1 ft and 2d day, a certain quantity of air was produced, 
about as much as in former like experiments. The 3d day very- 
little was produced ; and the 4th day none at all, the globe to all, 
appearance being quite exhaulted. Continuing the experiment, 
however, upon the 3 th day, the water having acquired a faint 
greenifh hue, air was again produced pretty plentifully, making 
its appearance upon the Jurface °J the leaves in the form of air~- 
bubbles r , 
