_)

In proportion as reflected lights are thrown upon a darker or lighter
ground, will their appearance be more or less brilliant. We deduce from
this, that all those reflexes, that brighten up and play so harmoniously
among the obscurity of shadows, must be in proportion to the strength of
the light that occasions them. (_Plate 4._)

The light made to graduate too softly, by means of the half-tint, into
the shadow, unless some part be boldly and cuttingly opposed to the
other, will have a tame and insipid appearance, however sharp and
forcible other portions of the work may be. (_Plates 3, 4._)

'_Fulness_ of effect is produced by melting and losing the shadows in a
ground still darker than those shadows: whereas _relief_ is produced by
opposing and separating the ground from the figure; either by light, or
shadow, or colour.' (_Plate 3, fig. 2._)

Any thing intercepting the line of light upon an object, will render its
shadows soft, and its lights beautifully blended.

Accidental shadows are those occasioned by objects interposed between
the light and the surface reflected on. Natural shadows, those which the
light connects with every opaque body. (_Plate 4, consists of natural
and accidental shadows._)

The outline of the shadow should partake of the forms, at its edges, of
the character of the surface receiving, as well as the one giving it.

In many, otherwise, excellent pictures of Claude's, the sun is placed
at, or near the point of sight: so that all the shadows, running from
that point, almost mechanically carry the eye into the picture. Whatever
of good may proceed from this arrangement, its purpose is too easily
detected; and it has an artificial effect.

Da Vinci says, 'The appearance of _motion_ is lessened, according to the
distance, in the same proportion as objects diminish in size.'

Open the side of a book against the light, and observe the gradations of
shadow on the leaf.

If you turn half a sheet of paper up against the light (in the manner of
the book), it will explain, by its shadows on the parallel part, the
phenomena of half or demi-tint.

In any body that has many indentures, there will be many shadows and
their grades: that body will have a greenish hue over its superfice,
where the light falls on it. To keep the colour of that light pure, in
this instance, requires great management; as the markings of the masses
of foliage, &c., receiving the light. And yet, without these markings