ricity) would have a bearing in importance far beyond all
conception in elucidating not only the facts connected with these
subjects, but also others of a high importance. There being scarcely a
limit to the subjects which would be illuminated by it."

"Gravity, surely this force must be capable of an experimental relation
to electricity and magnetism and the other forces, so as to bind it up
with them in reciprocal action and equivalent effect."--FARADAY.

KEPLER regarded gravity and heat "as being probably derived from one
single principle."

"There is every reason for believing that the radiations which
constitute heat and light are essentially the same."

"Gravity acts instantaneously."

_Static Electricity._

12. (Page 52.) Speaking of static electricity, FARADAY remarks: "What an
idea of the ever-present and ever-ready state of this power is given to
us, when we consider that not only every substance, but almost every
mode of dealing with substance manifests its presence. It is not
accidental at these times, but active and essentially so, and we may, in
our endeavors to comprehend it, usefully compare and contrast it with
gravity which never changes. There we see that power which in
undisturbed and solemn grandeur holds equally the world and the dust of
which worlds are formed together, and carries them on in their course
through illimitable space through illimitable ages; and in this other
power, even in this our first glimpse we see probably the contrasted
force which is destined to give all that vivacity and mutual activity to
particles that shall fit them as far as matter alone is concerned, for
their wonderful office in the phenomena of nature, and enable them to
bring forth the ever varying and astonishing changes which earth, air,
fire and water present to us; from the motion of the dust in the
whirlwind up to the highest conditions of life."

13. (Page 61.) An illustration of this form of wind-production may be
found in the following facts related by DR. GISLER, who for a long time
dwelt in the north of Sweden: "The matter of the aurora borealis
sometimes descends so low that it touches the ground. At the summit of
high mountains it produces upon the face of the traveller an effect
analogous to that of wind."

We should pronounce this effect to be the production of a true wind of a
circumscribed or local character.

_Solar Spectrum, its origin._