Dictionarium Polygraphicum: Or, The Whole Body of Arts Regularly Digested. Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV. 1735CERUSS a preparation of lead, commonly call'd white lead, and by the chymists calx of lead.
Cerus, is made of very thin laminæ or plates of lead, so laid as to receive and imbibe the fumes of vinegar, plac'd in a vessel over a moderate fire.
The laminæ, or plates, are by means hereof converted into a white rust, which is gathered together; and being ground up with water, is formed into little cakes.
Cerus, makes a beautiful white colour, and is much us’d by painters both in oil and water colours.
The best ceruss is that of Venice, but this is rare; that which is chiefly us'd, is either English or Dutch; both of which have more marl in them than white lead; the latter however is the better of the two.
CHROMATICK [in painting] a term used to fignify the colouring, which makes the third part of the art of painting.
COPAL. A gum of an agreeable smell, resembling that of incense brought from New-spain, where it oozes out from in cisions made in the bark of a large tree, much after the manner in which the vine yields its water, when cut in the spring. 'Tis very rare, when good, 'tis of a fine transparent yellow and melts easily. For want of this, there is another kind brought from the An tilles, which is almost the only one known among the druggists. Its chief consumption is in making varnish.
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