Linseed Oil.
—To ascertain with absolute certainty whether a sample of linseed oil is pure or not is by no means easy, and can only be done by aid of chemistry. There are various methods by which the adulteration can be ascertained, but we hesitate to print them here, because they may prove misleading to the uninitiated. The experienced painter has two tests of his own, viz., smell and the working of the oil, and if these lead him to suppose it is adulterated his only safe plan is to obtain the services of a competent chemist.
We next reach a consideration of the different qualities of the principal pigments, and can best show these by means of tables.
PIGMENTS.
Some Useful Tables.
Pigments Liable to Change under the Influence of Sulphuretted Hydrogen, Air, and Moisture:
Yellow.—Turner’s yellow, chrome yellow, mineral yellow, Naples yellow.
White.—Cremintz white, flake white, pearl white.
Red.—Red lead, purple red, iodine scarlet.
Green.—Verdigris, Scheele’s green, emerald green, mountain green.
Blue.—Prussian blue, Antwerp blue.
Orange.—Orange chrome.
Pigments Little Liable to Change under the Influence of Sulphuretted Hydrogen, Air and Mixture:
White.—Zinc white, constant white, tin white.
Red.—Vermilion, red ochre, Indian red, madder lakes.
Yellow.—Yellow ochre, barium chromate, zinc chromate, aureolin, raw sienna.
Green.—Chrome green, cobalt green.
Blue.—Ultramarine, smalt, Thenard’s blue.
Brown.—Vandyke brown, raw umber, burnt umber, manganese brown, sepia.
Black.—Ivory black, lamp black, Indian ink, graphite.
Orange.—Orange vermilion, burnt sienna.
Pigment Liable to Deterioration when in Contact with White Lead, Chrome or other Lead Pigment:
Yellow.—Yellow orpiment, king’s yellow, Indian yellow, gamboge.
Red.—Iodine scarlet, cochineal, carmine.
Orange.—Golden antimony sulphide, orange orpiment.
Green.—Sap green.
Blue.—Ultramarine.
Pigments which are Little Affected by Heat, and which may be Employed when the Material has to Stand Fire:
White.—Tin white, barium white, zinc white.
Red.—Red ochre, Venetian red, Indian red.
Yellow.—Naples yellow, antimony yellow.
Blue.—Smalt and royal blue, ultramarine.
Green.—Chrome green, cobalt green.
Orange.—Burnt sienna, burnt ochre.
Brown.—Burnt umber, manganese brown.
Black.—Graphite, mineral black.
Colours that may be Used with Lime:
White.—Permanent white, i.e., baryta white, gypsum, zinc white.
Red.—The vermilions, light red, Venetian red, Indian red, madder lakes.
Orange.—Cadmium, orange chrome, Mars orange, burnt sienna, burnt Roman ochre, light red.
Yellow.—Aureolin, cadmium yellow, lemon yellow, Naples yellow, Mars yellow, raw sienna, yellow ochre, Roman ochre, transparent gold ochre, brown ochre, Indian yellow, Oxford ochre.
Green.—Oxide of chromium, transparent oxide of chromium, viridian, emerald green, malachite green, verdigris, terre verte, cobalt green, chrome green.
Blue.—Genuine ultramarine, artificial ultramarine, new blue, permanent blue, cobalt blue, cerulean blue, smalt.
Purple.—Purple madder, Mars violet.
Brown.—Bone brown, bistre, Prussian brown, burnt umber, Vienna brown, Vandyke brown, Cologne earth, asphaltum, Cassel earth, manganese brown.
Citrine.—Raw umber, Mars brown.
Blacks.—Ivory black, lamp black, blue black, charcoal black, Cork black, Indian ink, black lead, drop black, plumbago.