252 J. Wharton on Autumnal Foliage. 
Reasoning thus one autumn day about ten years ago, I ar- 
ranged a wire staging, to stand under a glass receiver, which 
dipped into a dish of water, and under which was also placed 
a capsule containing ammonia, Upon this staging I placed in 
succession a variety of autumnal red leaves, and had the grati- 
fication to perceive that in most cases the green color was re- 
stored, 
The rapidity and completeness of this restoration varied 
greatly in different leaves ; while those which were covered by 
a thin and porous cuticle passed visibly from red to green be- 
fore the eyes, (for instance Sassafras, Blackberry, Maple, ete.), 
others, whose cuticles were comparable to an impervious varnish, 
(for instance some of the Oaks,) changed gradually into brown, 
_ without showing any trace of green, except sometimes ina few | 
spots where an imperfection in the leaf existed. | 3 
In order to determine fully whether the behavior of this lat- 
ter class of leaves was really owing to the protection afiorded 
to the pulp or chlorophyl ‘by the cuticle, | wounded se 
such oak leaves in divers spots, and found that although these 
leaves, when exposed to ammoniacal vapor, became generally 
brown, each wo 
___ #rost prob; 
tints, than m. 
eaves 1s still full and plump, the red colors come oUt” 
tly, because there is plenty of the blue substance to 
