most perfect way of doing
everything known up to that time: and if any one discovers a better, he
is to make it public forthwith. All of them taking care to embarrass
themselves with no theories or reasons for anything, but to work
empirically only: it not being in any wise their business to know
whether light moves in rays or in waves; or whether the blue rays of the
spectrum move slower or faster than the rest; but simply to know how
many minutes and seconds such and such a powder must be calcined, to
give the brightest blue.

Sec. XV. Now it is perhaps the most exquisite absurdity of the whole
Renaissance system, that while it has encumbered the artist with every
species of knowledge that is of no use to him, this one precious and
necessary knowledge it has utterly lost. There is not, I believe, at
this moment, a single question which could be put respecting pigments
and methods, on which the body of living artists would agree in their
answers. The lives of artists are passed in fruitless experiments;
fruitless, because undirected by experience and uncommunicated in their
results. Every man has methods of his own, which he knows to be
insufficient, and yet jealously conceals from his fellow-workmen: every
colorman has materials of his own, to which it is rare that the artist
can trust: and in the very front of the majestic advance of chemical
science, the empirical science of the artist has been annihilated, and
the days which should have led us to higher perfection are passed in
guessing at, or in mourning over, lost processes; while the so-called
Dark ages, possessing no more knowledge of chemistry than a village
herbalist does now, discovered, established, and put into daily practice
such methods of operation as have made their work, at this day, the
despair of all who look upon it.

Sec. XVI. And yet even this, to the painter, the safest of sciences, and
in some degree necessary, has its temptations, and capabilities of abuse.
For the simplest means are always enough for a great man; and when once
he has obtained a few ordinary colors, which he is sure will stand, and
a white surface that will not darken nor moulder, nor rend, he is master
of the world, and of his fellow-men. And, indeed, as if in these times
we were bent on furnishing examples of every species of opposite error,
while we have suffered the traditions to escape us of the simple methods
of doing simple things, which are enough for all the arts, a