Pigments And Bases Are Subject To Deoxidation Or To A Loss Of Oxygen
: ON COLOURS AND PIGMENTS GENERALLY.in which case the colour is apt to deepen. Pigments generally are more
affected by oxidation and fading in a water vehicle, and by deoxidation
and darkening in one of oil.
A principal test of permanency in pigments is the impunity with which
they bear exposure to light and air, an artistic proof of their
stability the mere chemist is apt to neglect. Provided the colour remain
unaffected by sulphuretted hy
pronounce it safe. But a pigment may be fast in one sense and fugitive
in another, believed in by the laboratory, and found wanting by the
studio. It has happened before now that the same colour has been dubbed
durable and the reverse, by the man of science and the man of art. The
former, we take it, looks upon a pigment as a coloured substance of a
certain composition, possessing maybe an acid and a base, either, or
neither, or both of which, gases and other reagents may injure or
destroy. The latter views a colour chiefly as part and parcel of his
More
-
Or Queen's Yellow Is A Subsulphate Of Mercury Of A Beautiful Lemon
yellow colour, but so liable to change by the action of light or impure air, that it cannot be used safely, and hardly deserves attention as a pigment. ... Or Quercitron Yellow Is What Its Name Implies It Is Dark In
substance, in grains of a glossy fracture, perfectly transparent, and when ground is of a beautiful yellow colour. In painting it follows, and adds richness and depth to, gamboge in water, and goes well into varnish; but any lead used in rendering oil... Or Rouge De Mars Is An Artificial Iron Ochre Similar In Subdued Tint
and permanence to the native earths. Its chemical affinities, however, are greater than those of the latter, and it therefore requires to be employed cautiously with pigments affected by iron. In this respect the red resembles its compeers, Mars yello... Or Swedish Green Resembles The Preceding Variety In Being A Compound
of copper and arsenic, and therefore rankly poisonous; but differs from it in containing no acetic acid, in possessing less opacity, and in having a darker shade. It is a cupric arsenite, with the common attributes of emerald green, under which name i... Or Viride Aeris Is Of Two Kinds Common Or Impure And Crystallized Or
... Orange As Well As Its Relatives Scarlet And Other Warm Colours
... Orange Chrome Or Orange Chromate Of Lead Is A Sub-chromate Of Lead
of an orange-yellow colour, produced by the action of an alkali on chrome yellow. Like all the chromates of lead, it is characterized by power and brilliancy; but also by a rankness of tone, a want of permanence, and a tendency to injure organic pigme... Orange De Mars Is A Subdued Orange Of The Burnt Sienna Class But
without the brown tinge that distinguishes the latter. Marked by a special clearness and purity of tone, with much transparency, it affords bright sunny tints in its pale washes, and combines effectively with white. Being an artificial iron ochre it i... Orange For Instance Which Is Naturally An Orange Pigment And Not
composed of red and yellow, is superior to many mixtures of those colours in a chemical sense, and to all such mixtures in an artistic sense. At the same time, it is quite possible for the artist to multiply his pigments unnecessarily. Colours are som... Orange Russet Russet Rubiate Or Field's Russet This Is A Very
rich crimson russet with a flush of orange; pure, transparent, and of a middle hue between orange and purple. Prepared from the madder root, it is not subject to change by the action of light, time, or mixture of other pigments. Although not so much e... Orange Vermilion
TTITLE VERMILION, Deep or pale, when well made and pure is of strict permanence, not sensibly affected by light, time, or foul air; and eligible either in water, oil, or fresco. For an enamel colour it is unsuited, being dissipated at a red heat,... Otherwise Called Berlin Blue Paris Blue Prussiate Of Iron
... Oxide Of Manganese Which Gives The Red Hue And That Of Cobalt Which
... Paint Its Colouring Matter Or Anchusin Has The Character Of A Resin
and is dark-red, softened by heat, insoluble in water, soluble in alcohol and alkalis, and freely so in ether, fats, and volatile oils, to all of which it imparts a brilliant red hue. To obtain anchusin, all the soluble matters are first abstracted fr... Pale Chrome And Deep Chrome Are Chromates Of Lead In Which The
latter metal more or less exists, according to the paleness or depth of the colour. Of modern introduction, they are distinguished for their brilliancy, their opacity and body, and their going cordially into tint with white, both in water and oil. Owi... Pale Vermilion Scarlet Vermilion Chinese Vermilion Carmine
... Peculiar Red Mineral Orange
... Pickle Green &c
The general characteristics of these greens are brightness of colour, well suited to the purposes of house-painting, but seldom adapted to the modesty of nature in fine art; considerable permanence, except when exposed to the action of damp and impu... Picture--that Picture Which May Meet With Foul Exhalations But Must
be exposed to light and air. And he too often thinks as little of the effects of an impure atmosphere or injudicious admixture, as the chemist considers the action of air and light. ... Pigment Says The Chemical News Supplies A Desideratum Hitherto In
vain sought for by artists. It is the nearest approach to a perfect yellow in existence, and more closely resembles the purity of the prismatic spectrum than any other artificial colour. It is transparent, has great brilliancy and richness, both pure ... Pigment The [greek: Kinnabari] Of The Greeks And The Minium--a Term
now confined to red lead--of older writers. Pliny states that it was so esteemed by the Romans, as to have its price fixed by express law of state. Among other places, the natural product is met with in California, Spain, and Peru; and in China there ... Pigments And Bases Are Subject To Deoxidation Or To A Loss Of Oxygen
in which case the colour is apt to deepen. Pigments generally are more affected by oxidation and fading in a water vehicle, and by deoxidation and darkening in one of oil. A principal test of permanency in pigments is the impunity with which they b... Pigments Of Whose Thorough Durability There Is No Doubt Comes The
... Pitch And [greek: Kallos] Ornament The Blue Is Named Pittacal
The mode of separating pittacal has not been clearly described. Dumas states, that when precipitated in a flocculent state from its solutions, or obtained by evaporation, it closely resembles indigo, and, like it, acquires a coppery hue when rubbed.... Plumbago Or Graphite Contains In Spite Of Its Name No Lead Being
simply a species of carbon or charcoal. In most specimens iron is present, varying in quantity from a mere trace up to five per cent, together with silica and alumina. Sometimes manganese and titanic acid are likewise found. It is curious that carbon ... Poppy &c: In Gold Colour &c It Leans Towards Yellow Combined
... Pre-eminently A Warm Colour Being The Equal Contrast Of Or Antagonist
... Predominates To The Eye Constitute The Negative Or Neutral Colours
... Primary Blue Yellow Furnishes All The Variety Of The Secondary
... Primary Colours Are Three Only Yellow Red And Blue They Are
such as yield others by being compounded, but are not themselves capable of being produced by composition of other colours. By way of distinction, they are occasionally designated "entire" colours. ... Primary Yellow The Secondary Orange Or The Tertiary Citrine With
... Principle Under The Name Of Wongshy And Consisting Of The
seed-capsule of a species of gentian. The aqueous extract, freed from the pectin which it contains, yields with baryta- and lime-water yellow precipitates, from which acids separate the colouring matter of a vermilion hue. When thus prepared it is ins... Produced By A Thin Wash Of Black Over White The Neutral Grey Differs
... Proportions Of Thirteen Purple To Three Yellow Measured In Surface
or intensity. Being nearest to the neutral white in the natural scale of colours, yellow accords with it in conjunction; while, of all colours, except white, it contrasts black most powerfully. Yellow is discordant when standing alone with orange, uns... Purple Being A Secondary Colour Composed Of Blue And Red It
follows of course that any blue and red pigments, which are not chemically at variance, may be employed in producing mixed purples of any required hue, either by compounding or grinding them together ready for use, or by combining them in the various ... Quoque
TTITLE PRIMARY BLUE ... Recommended For Painting If Not Too Thinly Applied
... Red And Blue In The Proportions Of Five Of The Former To Eight Of
the latter; proportions which constitute a perfect purple, or one of such a hue as will neutralize and best contrast a perfect yellow, in the ratio of thirteen to three, either of surface or intensity. When mixed ... Red Indian Ochre Scarlet Ochre Carnagione Terra Puzzoli
... Red Is The Archeus Or Principal Colour In The Tertiary Russet; Enters
... Red On The One Hand And Of The Middle Tertiary Russet On The
other; while, unlike the other secondaries, all its hues, whether tending to blue or yellow, are of the same denomination. These attributes of green, which render it so universally effective in contrasting colours, cause it also to become the least ... Requires Its Contrast Orange In Equal Proportion Whether Of Surface
or intensity, to compensate or resolve its dissonances and correct its coldness. In nature, however, blue is not discordant with either green or purple, nor are any two colours (as we have said before) ever found ...