ur hypothesis of an atomic,
gravitating and rotatory Aether medium.

He writes: "We shall conclude this chapter by the mention of two
phenomena, which to me indicate the existence of some slight degree of
nebulosity about the sun itself, and even to place it in the list of
nebulous stars. The first is that called the Zodiacal Light, which may
be seen any very clear evening soon after sunset, about the months of
March, April and May, as a cone or lenticularly-shaped light extending
from the horizon obliquely upwards, and following generally the course
of the ecliptic, or rather that of the sun's equator. The apparent
angular distance of its vertex from the sun varies, according to
circumstances, from 40 deg. to 90 deg., and the breadth of its base
perpendicular to its axis from 8 deg. to 30 deg. It is extremely faint
and ill-defined, at least in this climate, though better seen in
tropical regions, but cannot be mistaken for any atmospheric
meteor or aurora borealis. It is manifestly in the nature of a
_lenticularly-formed envelope surrounding the sun_, and extending
beyond the orbits of Mercury and Venus, and nearly, perhaps quite,
attaining that of the earth, since its vertex has been seen fully 90
deg. from the sun's place in a great circle. It may be conjectured to
be no other than the _denser part_ of that medium which we have some
reason to believe resists the motions of comets; loaded perhaps with
the actual materials of the tails of millions of those bodies of which
they have been stripped in their successive perihelion passage. If its
particles have inertia, they must necessarily stand with respect to
the sun in the relation of separate and independent minute planets,
each having its own orbit, plane of motion, and periodic time."

Let me call the reader's special attention to one or two statements of
Herschel's given in this extract, in order to see how these statements
harmonize with the view of the Aether submitted in this work. In the
first place he states its shape is that of a lenticularly-formed
envelope surrounding the sun, and extending beyond the orbits of Mercury
and Venus, and probably to our earth. This harmonizes with the shape of
the aetherial envelope as given in Art. 70. Then Herschel states it may
be the denser part of that medium which we have reason to believe
resists the motions of comets. That is exactly what it is, though
Herschel failed to show why it should be the denser part of the Aet