Introduced With Caution When Hue Is Of Greater Importance Than Shade
:
ON THE NEUTRAL, BLACK.
Even when employed as a shadow, without much judgment in its use, black
is apt to appear as local colour rather than as privation of light; and
black pigments obtained by charring have a tendency to rise and
predominate over other hues, subduing the more delicate tints by their
chemical bleaching power upon other colours, and their own disposition
to turn brown or dusky. For these reasons deep and transparent colours,
hich have darkness in their constitution, are better adapted as a rule
for producing the true natural and permanent effects of shade. Many
pictures of the early masters, and especially of the Roman and
Florentine schools, evince the truth of our remarks; and it is to be
feared the high reputation of these works has betrayed their admirers
into this defective employment of black.
Black substances reflect a small quantity of white light, which receives
the complementary of the colour contiguous to the black. By
'complementary' is meant that colour which is required with another
colour to form white light; thus, green is the complementary of red,
blue of orange, and yellow of violet, or vice versa; because green and
red, blue and orange, and yellow and violet, each make up the full
complement of rays necessary to form white light. Briefly digressing, we
give the following mode of observing complementary colours:--Place a
sheet of white paper on a table opposite to one of two windows admitting
diffused daylight[C] into a room; take a piece of coloured glass and so
place it that the coloured light transmitted through it falls over the
surface of the paper; then put an opaque object on the paper close to
the coloured glass. The shadow of this object will not appear black or
of the colour of the glass, as might be supposed, but of its
complementary colour; thus if the glass is red, the colour of the
shadow will be green, although the whole of the paper surrounding it
appears red. Similarly, if the glass is blue, the shadow will appear
orange; if it is green, the shadow will appear red; and so with other
colours. It is absolutely essential, however, to the success of this
experiment, that the paper be also illuminated with the white light
admitted from the other window.
It has been said that black substances reflect a small quantity of white
light, which receives the complementary of the colour contiguous to the
black. If this colour is deep, it gives rise to a luminous
complementary, such as orange, or yellow, and enfeebles the black; while
the other complementaries, such as violet or green, strengthen and
purify it. In colours associated with black, if green is juxtaposed
therewith, its complementary red, added to the black, makes it seem
rusty. Those colours which best associate with black are orange, yellow,
blue, and violet. It would be well to remember that black, being always
deeper than the juxtaposed colour, entails contrast of tone, and tends
to lower the tone of that colour.
Most of the black pigments in use are obtained by charring, and owe
their colour to the carbon they contain. As the objects of vegetal and
animal nature may be blackened through every degree of impurity by the
action of fire, black substances more or less fitted for pigments
abound. The following are the chief native and artificial black
pigments, or colours available as such:--
TTITLE BLACK LEAD,