Common Resin.
Red Ochre reduced into a fine powder.
Yellow Wax.
Oil of Turpentine.
These must be melted over a fire in the following manner, and the vessel
in which it is made should be capable of holding three times the
quantity required, to allow room for boiling up. An earthenware pipkin
with a handle is the best thing for the purpose, and a lid must be made
of tin to fit it. The luting will be rendered more or less brittle, or
elastic, as the red ochre prevails:
The wax is first melted, and then the resin; the ochre is then added in
small quantities, and stirred quickly with a spatula each time. When all
the ochre has been added, it must be allowed to boil six or eight
minutes; the turpentine is then added, and briskly stirred with the
spatula, and continue to boil it. There is considerable risk of the
mixture taking fire, and should it do so, the lid must immediately be
put on the vessel to extinguish it.
To ascertain the consistence of the luting, a little must be, from time
to time, dropped on a cool plate, or flat piece of iron. If it is too
soft, more of the ochre must be added to it; and if too hard, additional
wax and turpentine.