1811.] Liierary and Philosophiatl Intdhgence. 57-S 
Mrs. Agnes .Ibbetson has published 
an interesting paper on the Hairs of 
Plants. Slie shews that the idea of per¬ 
spiration in plants is an absoltite fable, 
originating from the poQrness of the mag¬ 
nifiers employed, and that what has beem 
taken fur perspiration is either a sort of 
hair, or instrument in that shape, for 
carrying water to the interior of plants, 
and performing many of those important 
services whicii their diminutive appear¬ 
ance made us overlook; or a sort of cryp- 
togamia plant, nourished by the dews of 
the atmosphere. And further, there is 
found in the corolla of flowers, and in 
the stem of trees, a clear transparent 
skin, wiiich, placed under the highest 
snagniiier, slinws no alteration of form, 
nor any aperture, and the same is found 
on the extenor of the cuticle, on each 
side of tfie leaf of all plants ; so tiiat it is 
not possible that a drop of water can 
pass to from the interior. No part of 
the vegetable structure plays so many 
parts, and shows itself in so many ways, 
as this delicate skin; through it she saw 
the dew drop enter the pabulum; of the 
same skin these hairs are formed, which 
confine not only water but air. How 
then, says she, can water enter the inte¬ 
rior of the leaf, which is thus guaided on 
both sides by tfiis transparent medium ? 
For ti.iat water which is often seen under- 
Jieath the skin of vegetables, and wliolly 
independent of the vessels, they are in¬ 
debted to the hairs alone. The first idea 
that occurs on seeing these hairs greatly 
magnified is, tliat they reseinhie the in- 
gtruments in an immense laboratory. 
But great indeed must be the laboratory 
that could show instruments of such con¬ 
trivance, figures so various, and mecha¬ 
nism so asfeonishing, even putting tiieir 
diminutive size out of question. By the 
most careful attention to their forms, by 
filling them with coloured liquids, and 
with art and constant practice learning to 
manage the iieat ami light of her solar 
microscope (opaque as well as common), 
?»]rs. Ihbetson was able repeatedly to fili 
and empty a few of the instruments, and 
by these means understand something of 
their construction. Innumerable are the 
offices which these hairs perform. They 
shade from light and heat, convey mois¬ 
ture, decompose water, catcli and secure 
drops of rail*) as they fa!!, and select the 
dew from the atmosphere. Yet but 
a small part of their offices aie the 
carrying moisture to the plants, catching 
tire rain-drops on their points, and de¬ 
fending the back of the leaf from the sun^s 
rays. The following figure represents st 
Monthly Mag. No. 219 . 
hair used, and purticularly found «n dr's 
Jeavesi of trees. 
This is merely a managed vacuum, which 
draws the water into the vessel, and then 
lets it into the pabulum of the leaf. 
When the buds of trees are enlarging, 
and maclt humidity is required for their 
preservation, a quantity of hairs suddenly 
cover ail the buds in various directionsj, 
shaped as beneath, 
The sort of instrument used on this occa¬ 
sion never varies, and selects the dew 
from the atmosphere ; at four or five in 
the morning rhey are almost empty ; by 
eight, perfectly full; again empty before 
noon, and late in the evening replenished 
to bursting, or, running over; but how 
they fill themselves, except by means of 
a vacuum, she has not been able to disco¬ 
ver. In p^irfumed plants Mrs. Ibbeupn 
found a species of instrument that baffled 
conjecture as to its management or uses, 
represented below, 
The 
