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 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 hydrogen, &c., he seldom hesitates to 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 Pigment The [greek: Kinnabari] Of The Greeks And The Minium--a Term Pigments Of Whose Thorough Durability There Is No Doubt Comes The ![]() ![]() ![]() ![]() ![]() ![]() ![]() Feedback |