The examiner. [volume] (Louisville, Ky.) 1847-1849, 1848-01-15

At late meeting Of the Royal Cornwall
Polytechnic Society, MIR. Hunt addressed
the company on the interesting subie Of
some recent discoveries. and which he him.
self originated, respecting the various pow.
ers Of the solar rays. About SIX years ago
ne announced that, associated with the light
and heat derived from the sun was another
principle, most active in producing extraor-
binary changes in the organic and inor-
ganic world. This principle he at first
called Energis; but since, on the sugges-
ton Of Sir John Herschel, i had been called
actinism Qrom the Greek akin, a ray oil
the SUM- Subsequent researches had es-
tablished the fact that the solar ray contains
three principles and distinct means Of &C
ton, light, heat, and actnism. His pres
ent observations referred to the influence,
separately and in combination, Of these three
principles on vegetation, showing that seeds
placed under the influence Of solar rays
that penetrated through yellow glass would
not terminate, because yellow glass pre-
vents passage Of the sctinic principle, with
its chemical action. Mr.. Hunt then illus
trsted, by explanations Of the VARIOUS effects
on vegetation Of different col,red glasses,
the necessity Of the combined influence Of
the three principles Of light, heat and acti-
nism, to the complete termination, growth,
and inAorescence Of plants.
He then showed how beautifully consist
ent with these discoveries were the arrange
meDts Of the Divine Being in the process Of
vegetation. During spring the solar beam
contained large amount Of the acCinic
principle, necessary at that SEASON for the
termination Of seeds and the development
Of buds. In summer there was large pro-
portion Of the light giving principle, neces-
sary TO the formation Of the woody portions
Of plants And towards autumn, the calori-
ic or beat giving principles Of the solar
rays increased. Mr, Hunt exhibited da-
grams, showing the proportions Of the three
principles as they had been observed to ex-
isl in The solar ray, in the seasons OF spring,
summer, and autumn. He then showed
how the vegetation Of different climates was
variousIy affected, according as they receiv-
ed different proportions Of the three cons.itu-
ent principles Of the solar beam. In prac-
teal application Of the results Of this theory
Mr.. Hunt spoke Of the injurious effects on
vegetation from the use in green houses of
the white German sheet glass. Under this
kind Of glass plants were subject TO an in
furious solar influence which they had not
suffered under the old crown glass.
1t became, therefore. necessary to dis
cover some means to cut of hose para
fhermic rays, which. passing through the
white glass, scorched and Drowned particu-
lar portions Of the leaves, without cutting
of the other portions Of the rays, which were
necessary to the growth Of the pant. This
remedy MIR. Hunt had discovered and ap-
piled at Kew Observatory. 1t was green
glass, stained with oxide Of copper, which
glass efectually excluded the injurious para
theTmic rays, while it admitted the other
solar rays necessary for the plaat as freely
as ordinary white glass. In the manuac-
ture Of this green glass it was essential that
no manganese should be used, as was the
case in white glass. II the manganese were
used the white glass would, after a While,
assume pinkish hue, which would more
freely admit the burning rays. Mr.. HINT
also spoke ofthe difference between morning
and afternoon rays in their effect on vege-
tation. and Of the probability of vegetation
being affected by the polarization Of light.