week of July, the whole of the stem was dry, and the tree itself dead.
In about fifteen days after the first, a tree, which joined the former a
little above the earth, shared the same fate, in consequence of its
connexion with that into which the poison had been introduced. Other
trees similarly cut, but without having been poisoned, suffered no kind
of injury.

M. Marcet's experiments upon vegetable poisons are no less interesting,
and still more wonderful, as indicating a degree of irritability in
plants somewhat similar to that which depends on the nervous system in
animals. After having ascertained that the bean plants could exist in a
healthy state for five or six days, if immersed in the same quantity of
spring water, he tried them with five or six grains of opium dissolved
in an ounce of water, the consequence of which was, that in the evening
the leaves had dropped, and, by the middle of next day, they were dead
beyond recovery. Other vegetable poisons of the narcotic class produced
a similar effect. Hemlock was equally fatal, and six grains of dry
powdered foxglove, in an ounce of water, began to operate, by wrinkling
some of the leaves of the bean in a few moments, which it completely
killed in twenty-four hours. Oxalic acid or salt of sorrel, though found
in common and wood sorrel, and a great many plants, proved a very fatal
poison to others. The absorption of one-tenth of a grain, killed a rose
branch and flower in forty--eight hours.--

_Quar. Jour. of Agriculture._

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