Burlington free press. [volume] (Burlington, Vt.) 1827-1865, 1840-05-08
EXCEPTIONS OF PLANTS.


The following notice Of some Of the
substances excreted by the stems and
leaves Of plants, is taken from work of
Prof Lindley: "Acid excretions are
formed by the hairs ofthe chick-pea, the
stag-horn sumacb and some other species;
and it is supposed that the singular pro-
pcrty which some lichens possess Of inn
bedding themselves in calcareous rocks is
owing to their excretion oxalic acid. The
singing power of the nettle is produced
by an acrid matter excreted by the hairs
with which their leaves and stalks are COW
cred. The nettles Of Europe simply pro-
duced an uneasy sensation, but some of
those of India have brought on lock-jaw,
and oven death itself by the torments
which they inAict. Adischarge Of sticky
matter by the hairs or by the bark of
plants, is Of very common occurrence.
1t is this which gives their viscidity to
such plants as the rose acacia, to the buds
of the horse chestnut, and to the young
leaves of the beech tree. In many cases
this sticky matter is analogous in compo-
sltion to common bird lime. Wax, or
some substance analogous to it, is of very
common occurrence on the surface Of
plants. Sacharine matter, in different
forms, is also common cxcreton from
many plants. European mama is dis
charged by the Towering ash (fra1inus
ornus, either in consequence Of wounds
articlally inflicted on the branch, or Of
the puncture ofinsects. The mamma spo-
ken of in scripture is yielded by species
oftamarsk, and by the camels-thorn, a
plant which is common in the deserts Of
southern Asia. But the most curious in
stance Of matter excreted from the leaves
is afforded by the fraxinella. The leaves
ofthis plant are covered with little brown
glands, which excrete species of vola-
tile oil. In warm weather this oil is con-
vcrted into vapor and surrounds the plant
as an inflammable atmosphere, readily
taking fire when a flame is brought ii
contact with it, and burning without do
ing any injury to the plant"
The possession of the power of reject
ing such matter as is found unsuitable TO
their nourishment, would seem to be
necessary condition of the life Of plants
Did they not possess it, their vessels mus
soon become cloggod, and rendered unf
for their nourshmcnt. Macaire took
plant ofmcrcury (mcrcmials annua, ) an
having divided its roots into two parcel:
introduced one of them into glass con
tanning weak solution of acetate ofleae
and the other into glass of pure waite
At the end of few hours he found tn;
the glass of pure water had become pei
ceptibly tingcd with acetate of lead ,whic
of course must have been taken into I'll
circulation by the roots on one side of II
plants, and thrown of again by the roo
on the other. In this instance the cS
GREETED matter was thrown back witho
having undergone any change: as a gel
cral thing, however, this is not the case
thus, leguminous plants, of which the pc
may be mentioned as an example, a
though they absorb only carbonic &C
and water, will excrcte the elements
those substances combined so as to for
species ofgum. Grasses eXcrete pri
cipally certain alkaline and earthly m
riatcr and carbonates, but very little
any gum.-Idrmer's Register.