h with all diffidence.

122. We must not, however, pass entirely without notice the two chapters
on the preparation of oils, and on the oleo-resinous vehicles, though to
the general reader the recipes contained in them are of little interest;
and in the absence of all expression of opinion on the part of Mr.
Eastlake as to their comparative excellence, even to the artist, their
immediate utility appears somewhat doubtful. One circumstance, however,
is remarkable in all, the care taken by the great painters, without
exception, to avoid the yellowing of their oil. Perfect and stable
clearness is the ultimate aim of all the processes described (many of
them troublesome and tedious in the extreme): and the effect of the
altered oil is of course most dreaded on pale and cold colors. Thus
Philippe Nunez tells us how to purify linseed oil "for white and blues;"
and Pacheco, "el de linaza no me quele mal: aunque ai quien diga que no
a de ver el Azul ni el Blanco este Azeite."[17] De Mayerne recommends
poppy oil "for painting white, blue, and similar colors, so that they
shall not yellow;" and in another place, "for air-tints and
blue;"--while the inclination to green is noticed as an imperfection in
hempseed oil: so Vasari--speaking of linseed-oil in contemporary
practice--"benche il noce e meglio, perche ingialla meno." The Italians
generally mixed an essential oil with their delicate tints, including
flesh tints (p. 431). Extraordinary methods were used by the Flemish
painters to protect their blues; they were sometimes painted with size,
and varnished; sometimes strewed in powder on fresh white-lead (p.
456). Leonardo gives a careful recipe for preventing the change of color
in nut oil, supposing it to be owing to neglect in removing the skin of
the nut. His words, given at p. 321, are incorrectly translated: "una
certa bucciolina," is not a husk or rind--but "a thin skin," meaning the
white membranous covering of the nut itself, of which it is almost
impossible to detach all the inner laminae. This, "che tiene della natura
del mallo," Leonardo supposes to give the expressed oil its property of
forming a _skin_ at the surface.

123. We think these passages interesting, because they are entirely
opposed to the modern ideas of the desirableness of yellow lights and
green blues, which have been introduced chiefly by the study of altered
pictures. The anxiety of Rubens, expressed in various letters, quoted at
p. 516, lest any o