USED IN PAINTING. HI
C L A s s V. Of orange colours.
There is not any Ample pigment, prepared. Commonly, which can properly come into this clafs: the effect of orange being produced in practice by the mixture of red and yellow: but the following preparation being of my own invention, and Serviceable to fome who have already made confiderable ufe of it, I thought it proper to inlert it for the benefit of others who may want fuch a pigment.
Of orange lake.
This orange lake is the tinging part of an- natto precipitated together with earth of alum. It is of a very bright orange colour, and would work well with either oil or water; but cannot be depended upon, when ufed either of thofe ways, for (landing long. It is, however, a very fine colour for varnilh painting, where the fear of flying is out of queftion ; and is alfo of an admirable good effedl for putting under chrydal for the imitation of the vinegar garnet; for which purpofe it has been ufed with great fuccefs.
The manner of the preparation of the orange lake may be as follows.
“ Take of the bed annatto four ounces, “ and of pearl-adies one pound. Put them “ together into a gallon of water, and boil “ them half an hour; and then drain the fo-
“ lution
112 OF THE SUBSTANCES “ lution through paper. Make, in the mCait “ time, a folution of a pound and a half of “ alum, in another gallon of water: and mix “ it gradually with the folution of the pearl- “ afhes and annatto; obferving to ceafe any “ further addition when the fluid becomes “ colourlefs, and no further ebullition enfues “ on the commixture. Treat the fedimeiit “ or precipitated matter, then, in the lame “ manner as has been before directed for o- “ ther kinds of lake; only this need not be ic formed into drops; but may be dried in “ fquare bits or round lozenges.”
CLASS VI. Of purple colours.
Of the true Indian red.
The true Indian red is a native ochrous earth, of a purple colour ; and, before the cheapnefs of the fidtitious kind, occafloned it to be rejected by the colourmen, and confe- quently difufed by painters; was conftandy brought from the EaJft Indies, and fold in the {hops. At prefent it is very rarely to be found; but when it can be met with, it is certainly very valuable (there being no other, uncompounded purple colour in ufe with oil) as well for the force of its effedt, as for the certainty of its {landing: but the common kind, now fallacioufly called by its name, has been, by degrees, from accommodating it to the purpofes of houfe painters, made to vary
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