at exploiting.
Nature is sufficiently vast for beautiful work to be done in separate
departments of vision, although one cannot place such work on the same
plane with successful pictures of wider scope. And the particular visual
beauty of sparkling light and atmosphere, of which he was one of the
first to make a separate study, could hardly exist in a work that aimed
also at the significance of beautiful form, the appeal of form, as was
explained in an earlier chapter, not being entirely due to a visual but
to a mental perception, into which the sense of touch enters by
association. The scintillation and glitter of light destroys this touch
idea, which is better preserved in quieter lightings.

There is another point in connection with the use of thick paint, that I
don't think is sufficiently well known, and that is, its greater
readiness to be discoloured by the oil in its composition coming to the
surface. Fifteen years ago I did what it would be advisable for every
student to do as soon as possible, namely, make a chart of the colours
he is likely to use. Get a good white canvas, and set upon it in columns
the different colours, very much as you would do on your palette,
writing the names in ink beside them. Then take a palette-knife, an
ivory one by preference, and drag it from the individual masses of paint
so as to get a gradation of different thicknesses, from the thinnest
possible layer where your knife ends to the thick mass where it was
squeezed out of the tube. It is also advisable to have previously ruled
some pencil lines with a hard point down the canvas in such a manner
that the strips of paint will cross the lines. This chart will be of the
greatest value to you in noting the effect of time on paint. To make it
more complete, the colours of several makers should be put down, and at
any rate the whites of several different makes should be on it. As white
enters so largely into your painting it is highly necessary to use one
that does not change.

The two things that I have noticed are that the thin ends of the strips
of white have invariably kept whiter than the thick end, and that all
the paints have become a little more transparent with time. The pencil
lines here come in useful, as they can be seen through the thinner
portion, and show to what extent this transparency has occurred. But
the point I wish to emphasise is that at the thick end the larger body
of oil in the paint, which always comes to t