The panel should be cypress or pear or service-tree or walnut. You
must coat it over with mastic and turpentine twice distilled and
white or, if you like, lime, and put it in a frame so that it may
expand and shrink according to its moisture and dryness. Then give
it [a coat] of aqua vitae in which you have dissolved arsenic or
[corrosive] sublimate, 2 or 3 times. Then apply boiled linseed oil
in such a way as that it may penetrate every part, and before it is
cold rub it well with a cloth to dry it. Over this apply liquid
varnish and white with a stick, then wash it with urine when it is
dry, and dry it again. Then pounce and outline your drawing finely
and over it lay a priming of 30 parts of verdigris with one of
verdigris with two of yellow.
[Footnote: M. RAVAISSON'S reading varies from mine in the following
passages: