The Artist's Assistant, In the Study and Practice of Mechanical Sciences: Calculated for the Improvement of Genius. Illustrated with Copper-Plates (Birmingham, [ca. 1785])

m THE ARTIST'S ASSISTANT.

Of ftaining ivory, bone, and horn, green.—They
mud be boiled in a folution of verdigrife in vi-
negar, or of copper in aquafortis, prepared as above
directed (a veffel of glafs or earthenware being
employed for this purpofe) till they be of the co-
lour dehred.

Of ftaining ivory, bone, and horn, red.—Take
flrong lime water, prepared as for other purpofes,
and the rafpings of brafil wood, in the proportion
of half a pound to a gallon. Let them boil for an
hour, and then put in the ivory, &c. prepared by
boiling in alum water in the manner above directed
for the yellow; and continue it there till it be fuf-
ficiently coloured. II it be too crimfon, or verge
toward the purple, it may be rendered more fcarlet,
by dipping again in the alum water.

Of ftaining ivory, bone, and horn, blue—Stain
the ivory, &c. firft green, according to the manner
above directed ; and then dip it in a folution of
pearl afhes made ftrong and boiling hot; but it muft
not be continued longer, nor dipt oftener, than is
neceffary to convert the green to blue.

The ivory, &c. may otherwife be boiled in the
tincture of indigo, prepared as by the dyers, and af-
terwards in the folution of tartar, made as is di-
rected for the ftaining wood.

Of ftaining ivory, bone, and horn, purple.—Treat
them in the fame manner as was directed for red, ex-
cept that logwood muft be fubftituted in the place
of brafil wood, and the ufe of the alum water muft
be omitted wholly.

If a redder purple be wanted, a mixture of the
logwood and brafil muft be employed, inftead of the
logwood alone. The proportion may be equal parts ;

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