Yellow ochre is usually employed in the distance and middle ground of a landscape. It possesses a slight degree of turbidness, and is esteemed for this property, which is considered to give it a retiring quality. By admixture with Antwerp blue or indigo it affords a fine range of quiet greens, also a very serviceable yellowish drab with Vandyke brown. The ochre is valuable in warm skies, the sails of ships and boats, sandstone rocks and cliffs, buildings, hay, sheep, &c. It does not compound kindly with any of the cold colours, and should therefore be used as a wash over others that are dry, when required to qualify their tints. 42. ROMAN OCHRE Is rather deeper and more powerful than the preceding, as well as more transparent and cool in tint. In other respects it is similar, and forms with Antwerp blue and indigo a like excellent range of greens. We may observe, however, that as indigo is not a permanent pigment, the colours it yields by admixture cannot be durable as far as the blue is concerned. Roman ochre and brown madder are admirably adapted for red sails, and autumnal effects of foliage. 43. BROWN OCHRE, Likewise known as _Spruce Ochre_ and _Ocre de Rue_, or, more correctly _Ru_, is a dense, deep-toned brownish yellow, fine in sandy foregrounds. With Indian yellow it gives a dark autumnal tint of great richness, but stable only as respects the ochre. When mixed with other colours, it furnishes a series of rich yet sober tones of extensive use. It covers well, without being too opaque; and compounded with black and a little brown-red is good for backgrounds, &c. 44. TRANSPARENT GOLD OCHRE Resembles in a great degree Roman ochre, but is clearer in its tints, and more transparent. It is also brighter and much less opaque than yellow ochre. It approaches somewhat the character of clear bright raw sienna, though more pure and brilliant, serving for strong semi-transparent greens and sunny effects. 45. OXFORD OCHRE Is a native pigment from the neighbourhood of Oxford, semi-opaque, of a warm yellow colour and soft argillaceous texture, absorbent of water and oil, in both of which it may be safely employed. It is one of the best of yellow ochres. 46. STONE OCHRE Has been confounded with the last variety, to which, as well as to Roman ochre, it is frequently similar. True stone ochres are found in balls or globular masses of various sizes in the solid body of stones, lying near the surface of rocks among the quarries of Gloucestershire and elsewhere. These balls are smooth and compact, in general free from grit, and of a powdery fracture. They vary exceedingly in colour, from yellow to brown, murrey, and gray, but otherwise do not differ from ordinary ochres. In enamel they may be used for browns and dull reds. 47. DI PALITO Is a light yellow ochre, with no special distinguishing quality, except that its tints are rather purer in colour than most ochres. 48. ORIENT YELLOW