PLANTS. 
15 
ec On the 12th of January I placed several shrubs 
in pots against the windows of my hot-house, some 
within the house and others without it. Through 
holes made for this purpose in the panes of glass, 
I passed a branch of each of the shrubs, so that 
those on the inside had a branch without, and those 
on the outside one within ; after this, I took care 
that the holes should be exactly closed and luted. 
This inversed experiment, I thought, if followed 
closely, could not fail of affording sufficient points 
of comparison to trace out the differences by the 
observation of the effects. 
“ The 20th of January, a week after this dispo- 
sition, all the branches that were in the hot-house 
began to disclose their buds. In the beginning of 
February there appeared leaves ; and towards the 
end of it, shoots of a very considerable length, 
which presented the young flowers. A dwarf apple- 
tree, and several rose-trees, being submitted to the 
same experiment, showed the same appearance then 
as they commonly put on in May: in short, all the 
branches which were within the hot-house, and 
consequently kept in the warm air, were green at 
the end of February, and had their shoots in great 
forwardness. Very different were those parts of the 
same tree which were without, and exposed to the 
cold. None of these gave the least sign of vegeta- 
tion; and the frost, which was intense at that time, 
broke a rose pot placed on the outside, and killed 
some of the branches of that very tree which, on 
the inside, was every day putting forth more and 
