CHANGEABLE TASTE OF PLANTS. fa! 
rican forests every air wafts its burden of the rich 
and varied perfume of the orchid-flower? Because 
here the light-gates of heaven are widest open ; 
and here the genial, ever active and all-powerful 
solar rays, quicken into existence products un- 
known save by report to less favoured regions. 
A very curious effect of light of a different kind 
has been noticed in a plant which is a native of 
India, named the Bryophyllum Calycinum. The 
juice of this plant is said, on good authority, to be 
quite acid in the morning, to be tasteless in the 
middle of the day, and, more singular still, to 
be bitter at night. This plant is not peculiar. 
Liebig, the eminent German chemist, cites an- 
other example in the Cacalia ficoides. The pro- 
bable explanation of this strange alternation of 
properties is, that during the night the plant 
absorbs oxygen gas, during the lght of the 
morning it loses it again, and at eventide, having 
lost still more, it acquires a positively bitter taste. 
Let us turn aside for a moment to speak of 
a series of most singular experiments, which have 
been instituted by several philosophers, and par- 
ticularly by Mr. R. Hunt, on the influence of 
different kinds of ight upon plants. Six boxes 
