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
•from
USED IN PAINTING. ir^ from It till it is become intirely a different co- •lour, being a broken orange inftead of a purple.
The true Indian red, when it can be procured, needs no other preparation than grinding or wafhing over: and it may be eafily di- ftinguifhed from any fictitious kind, by its being more bright than any other oker which can be made fo purple j and if it be rendered artificially purple by any addition, the fire will loon betray it j into which the genuine may be put without any hazard of change.
Of archal or orcbaL
Archal is a preparation of logwood by means of lime and fhreds of leather. It is an ex- ' tareme bright purple fluid; and would be. a -beautiful wafh, if it could be depended upon; but it is apt to dry to a reddilh brown colour j and therefore at prefent much difufed in painting j though it had formerly a place in the common fet of water colours. It is ufed in great quantities for fome purpofes of dying, by people who make it their bufinefs; and may be bad cheap of them, or the dry falters j but is Scarcely worth the trouble of procuring.
Of the tog'wood-'wajk.
Logwood is brought from America j and affords a ftrong purple tindture in water > which will ftain, of a bluifh purple colour, al- I molt
moft any body whatever capable of receiving fuch tinge. It is nfed frequently in miniature painting to make a purple wafh; which. » varied to a more red or blue colour by:, the addition or omiffion of Brafii wood. This -wafh may be prepared in the following sn^tkr ner. ‘ ‘ ’ .. : : . i/t
“ Take an ounce of ground logwoodj and “ boil it in a pint of wa&jr rill one half of.the “ fluid be wafled. Strain it thpn through “ flannel whife of a boiling heat; and add to “ it, when grained, ahout ten grains of.peaii- “ afhes, or about the bulk of a fmall French “ bean. If it |ae to be a more red
“ purple, about half an ounce of Brafil wood “ may be added to the logwood; or in/pro- “ portion as the . colour wanted: may require; “ and in this cafe the pearl-afhes muftbe “ ufed very fjjaririgly, or. nop added ot aD, “ unlefs the tincture appears too red.