Oil Painting was introduced in Flanders by the brothers Van Eyck in 1410, and in Italy by Antonello da Messina in or about 1455.

Oillets or Oylets. Loopholes.

Oils. The fixed oils used in painting are linseed, walnut, and poppy, purified and rendered drying by the addition of litharge. They should be pale in colour, limpid, and transparent, and should dry quickly: nut oil in a few hours, linseed in a day, and poppy oil in thirty-six to forty hours. The essential oils used in painting are turpentine, for diluting the pigments ground in oil, and spike, or lavender, for wax and enamel painting.

Oinerusis, Gr. (οἰν-ήρυσις). (See Arystichos.)

Ointment-box, in Christian art, is the attribute of St. Mary Magdalene, St. Joseph of Arimathæa, and other saints.

Fig. 500. Covered Tazza; Faience of Oiron. In the Louvre.

Oiron, a small town in France (so named from the flocks of geese which circle round it Oi-rond in winter), is the place where the fine faiences, usually called Henri II. ware, were made. “Here is France,” says M. Jacquemart, “in the 16th century in possession of a pottery, the discovery of which is attributed 200 years later to England.” There are only about fifty pieces known, five of which may be seen in the South Kensington Museum.

Okel, Egyp. A caravanserai. A large covered court surrounded by two stories of galleries, of which the lower is used as shops, &c., and the upper one as lodging-rooms.

Oldham. A coarse kind of cloth originated at Oldham in Norfolk, temp. Richard II.