nted pictures. We have now a
picture before us which was disagreeably oily, and yet did not well bear
out. We laid it on the grass, face uppermost, where it lay for about ten
days during heat and cold, day and night, dry weather and wet, and in
some few burning days exposed to the sun; during these hot days, we had
it frequently, plentifully washed with water, left on for the sun to
take up. We have this day removed the picture to the easel. The "oily
appearance" was gone, it was very dry, but pure, and clean, and bore out
equally, but rather like distemper. It is a question worth considering,
whether the atmosphere did not take up the impurities of the oil, which
always come to the surface.

There is proof enough of this. A picture, unless it be painted with very
little oil indeed, will become, in a few days after being painted,
greasy--it will not take water on the surface--in fact, "secca teme
acqua" will not bear water. If, in this state, the surface be lightly
rubbed over with common sand and water, this greasiness will be removed,
and the surface will not only be clean, but beautiful; this greasiness
will, however, in a day or two come again. If the process of sanding be
repeated, _until the greasiness does not_ come again, we conjecture that
we have done for the picture what time, but a long time, might do--we
have removed _all_ the impurity of the oil. We believe that pictures
after that do not undergo further change, and if the paint be tolerably
hard, may be varnished--and that they will become much sooner hard; for
it is more than probable that this greasiness in the oil is the main
cause of retarding the drying. We have followed this practice many
years, and always with the same results. It is surprising how soon after
painting you may sand--even coarse red sand will not remove paint, that
is yet tacky--it much remedies the "colori olcesi." The translator lays
much stress in the preface upon the importance of white grounds. In the
olden time, it appears, that when they were not of gold, they were
white; and Leonardo da Vinci thus lays down _his_ precept--"Sempre a
quelli colori che vuoi che habino belleza preparerai primo il campo
_candidissimo_, e questo dico de' colori che sono transparenti, perche a
quelli che non sono transparenti non giova campo chiaro." And yet
Leonardo is said to have painted occasionally on the canvass without any
other priming than a coat of glue. His pictures so painted are said to