When the sun is in the East all the portions of plants lighted by it
are of a most lively verdure, and this happens because the leaves
lighted by the sun within the half of the horizon that is the
Eastern half, are transparent; and within the Western semicircle the
verdure is of a dull hue and the moist air is turbid and of the
colour of grey ashes, not being transparent like that in the East,
which is quite clear and all the more so in proportion as it is
moister.
The shadows of the trees to the East cover a large portion of them
and are darker in proportion as the foliage of the trees is thicker.
446.