OF LIGHT AND LUSTRE.

What is the difference between light and the lustre which is seen on
the polished surface of opaque bodies?

The lights which are produced from the polished surface of opaque
bodies will be stationary on stationary objects even if the eye on
which they strike moves. But reflected lights will, on those same
objects, appear in as many different places on the surface as
different positions are taken by the eye.

WHAT BODIES HAVE LIGHT UPON THEM WITHOUT LUSTRE?

Opaque bodies which have a hard and rough surface never display any
lustre in any portion of the side on which the light falls.

WHAT BODIES WILL DISPLAY LUSTRE BUT NOT LOOK ILLUMINATED?

Those bodies which are opaque and hard with a hard surface reflect
light [lustre] from every spot on the illuminated side which is in a
position to receive light at the same angle of incidence as they
occupy with regard to the eye; but, as the surface mirrors all the
surrounding objects, the illuminated [body] is not recognisable in
these portions of the illuminated body.