vivid reflection from the concave side of the
cylinder, that is, from the concave surface of the Air that incompasses the
back-part of the cylinder; the other yielding a dull and perturb'd
reflection from the several _Heterogeneous_ parts that compose it. And this
difference will be manifest enough to the eye, if you get a couple of small
Cylinders, the smaller of Crystal Glass, the other of Horn, and then
varnishing them over very thinly with some transparent colour, which will
represent to the naked eye much the same kind of object which is
represented to it from the filaments of Silk and Hair by the help of the
_Microscope_. Now, since the threads of Silk and Serge are made up of a
great number of these filaments, we may henceforth cease to wonder at the
difference. From much the same reason proceeds the vivid and lovely colours
of Feathers, wherein they very farr exceed the natural as well as
Artificial colours of hair, of which I shall say more in its proper place.

The Teguments indeed of creatures are all of them adapted to the peculiar
use and convenience of that Animal which they inwrap; and very much also
for the ornament and beauty of it, as will be most evident to any one that
shall attentively consider the various kinds of cloathings wherewith most
creatures are by Nature invested and cover'd. Thus I have observed, that
the hair or furr of those Northern white Bears that inhabite the colder
Regions, is exceeding thick and warm: the like have I observ'd of the hair
of a _Greenland_ Deer, which being brought alive to _London_, I had the
opportunity of viewing; its hair was so exceeding thick, long and soft,
that I could hardly with my hand, grasp or take hold of his skin, and it
seem'd so exceeding warm, as I had never met with any before. And as for
the ornamentative use of them, it is most evident in a multitude of
creatures, not onely for colour, as the Leopards, Cats, Rhein Deer, _&c_.
but for the shape, as in Horses manes, Cats beards, and several other of
the greater sort of terrestrial Animals, but is much more conspicuous, in
the Vestments of Fishes, Birds, Insects, of which I shall by and by give
some Instances.

As for the skin, the _Microscope_ discovers as great a difference between
the texture of those several kinds of Animals, as it does between their
hairs; but all that I have yet taken notice of, when tann'd or dress'd, are
of a Spongie nature, and seem to be constituted of an infinite company