zinc, strontium, cadmium, and cobalt. There
appears to be no trace of gold, silver, mercury,
aluminium (the base of clay), tin, lead, antimony,
nor arsenic.

But this discovery is immediately followed by
a most important corollary. For black stripes
to show themselves in the solar spectrum, there
are required, first, a burning gas containing
metallic vapours; and, secondly, behind the
lighted gas, a non-gaseous body in a state of
ignition. As a natural consequence, the sun,
according to M. Kirchhoff, can be no other than
a solid or liquid incandescent globe, enveloped
in an atmosphere of very dense vapours.

This conclusion is, however, open to a very
serious objection. If the sun be solid, or even
only liquid, the cause of his spots can exist only
in his atmosphere; they must be merely
superficial, flat. M. Kirchhoff has therefore revived
Galileo's notion of the formation of opaque clouds
in the solar atmosphere.

But, on the other hand, the best observations
show unmistakably that the spots on the sun are
real cavities. From stereoscopic views a clear
idea is formed of the central hollow presented by
each spot. It is impossible, supposing them
superficial, to explain the striking and variable
appearances presented by the solar spots. In
this particular, the new theory accords ill with
observation.

M. Faye reconciles the difficulty by recalling
to mind Arago's famous experiment on the
polarisation of solar light, by which he proved that
that light must emanate from a gaseous medium.
On the other hand, Messieurs Bunsen and
Kirchhoff make the sun's light proceed from a
liquid or solid incandescent nucleus. M. Faye
gives a novel interpretation of the two experiments
which causes the difficulty to disappear,
thus: For Arago, the solar light emanates from
an incandescent gas; while Kirchhoff holds
that, behind the gas, there exists a solid source
of light. M. Faye makes them agree, by observing
that, doubtless, solid incandescent particles,
suspended in a gaseous medium, act in the same
way as a solid source of light, and so produce
the black bands. Suppose the sun to be still in
a gaseous state, and suppose solid particles of
matter to be held in suspension in the gas, and
the two contradictory experiments will mutually
support each other. The sun, therefore, is not
solid, nor even liquid, but gaseous; which quite
accords with his feeble mean density, already
referred to. The comets have been called
"visible nothings;" the sun is a very visible and
sensible "not much."

There is nothing, continues M. Faye, to
distinguish our sun from the multitudinous stars
which shine in the firmament. Astronomers
readily admit that the sun is a star of middling
magnitude, emitting light which is nearly white,
with a very slightly marked character of
periodical variability. We are therefore in the
presence of a phenomenon which is undoubtedly
of great importance to us, but which is at the
same time extremely common in the stellar
universe. Starting, therefore, with the simplest and
most general idea, and the one most applicable to
the aggregate of stars, we have the successive
union of matter in vast masses, under the
empire of attraction, out of the materials primitively
disseminated throughout space.

The star is in the state of a nebula; but at
length a cooling takes place at the surface: the
disunited elements gradually acquire the power
of approaching each other, and chemical affinities
are developed. The particles thus formed,
acted on by gravity, will descend towards the
lower strata, where, meeting with the temperature
of dissociation, they will be sent up again
as masses of gas. There are thus produced
vertical movements of reciprocal exchange,
which incessantly renew the emission of heat
and light. At the outer circumference will be
formed the apparent limit of the sun. The
vertical currents which agitate the mass easily
explain the appearances of the spots. Wherever
the ascending currents find an outlet, they
open a sort of vista into the interior, which
appears to the eye comparatively black, in
consequence of its lower radiating power. Father
Secchi ascertained, by means of thermo-electric
measurements, that the central portion of the
spots on the sun is less hot than the superficial
region.

It would appear then, if M. Faye's views be
correct, that a star passes through several
perfectly distinct phases. The first is the nebulous
condition, in which our sun no longer remains.
In the second phase, the outer strata are
sufficiently cooled to allow the play of certain
molecular affinities to be possible. There is
then formed a sort of superficial laboratory,
which determines the apparent outline of the
star. The emission of light and heat is
considerable, and is maintained at the expense of
the entire mass by the action of ascending and
descending currents which are established
between the deep strata and the surface. This
phase lasts for an immense lapse of time, and
presents great fixity in its phenomena. Our
sun is now passing through this very phase.
The vertical currents in his mass suffice to
account for every appearance hitherto observed.

The third phase arrives when, in consequence
of cooling, the vertical movements begin to
slacken; when, the entire mass gradually
contracting, the luminous surface little by little
acquires a liquid, a pasty, and finally a solid
consistence. From this condition, the sun is
still far distant. By continued cooling, at last
come the phenomena of definitive extinction.
Although the interior may be incandescent, the
exterior is covered with an opaque, cool, and
habitable crust. This is the geological phase.

Examples are recorded in history. The
seventh star of the Pleiades, after languishing
for centuries, went out at the fall of Troy.
Hevelius, a celebrated German astronomer,
mentions five stars whose expiring rays he had
the glory and sorrow to catch in his telescope.
Herschel, after ascertaining the disappearance
of a notable number of stars, by the comparison
of ancient with recent catalogues, had also the