or _Penley's Neutral Orange_, is a permanent compound pigment composed of yellow ochre and the russet-marrone known as brown madder: it is chiefly valuable in water-colour. Paper, being white, is too opaque to paint upon, without some wash of colour being first passed over it; otherwise the light tones of the sky are apt to look crude and harsh. It must, therefore, be gone over with some desirable tint, that shall break, in a slight degree, the extreme brilliancy of the mere paper. For this purpose, a thin wash of the orange is to be put over the whole surface of the paper with a large flat brush, care being taken never to drive the colour too bare, _i.e._ never to empty the brush too closely, but always to replenish before more is actually required. This first wash of colour not only gives a tone to the paper, but secures the pencil sketch from being rubbed out. The reason why, in this compound, yellow ochre, as a yellow, is preferred to any of the others, is, that it is a broken yellow, that is, a yellow slightly altered by having another hue, such as red, or brown, in its composition. It is somewhat opaque too, and hence, from this quality, is especially adapted for distances. Brown madder also is a subdued red, which, when in combination with the former, produces a neutral orange, partaking of the character of soft light. As a general rule, yellow ochre is to predominate in broad daylight, and brown madder in that which is more sombre and imperfect: hence the pigment can be yellowed or reddened, by the addition of one or the other. For a clear sunset, the neutral orange must be repeated, with a preponderance of ochre at the top, assisted by a little cadmium yellow near the sun; the madder being added downwards. In treating of distant mountains, a distinction is to be made between them and the clouds, the former requiring solidity, while the latter are only to be regarded as vapour and air. Mountains, being opaque bodies, are acted upon by atmosphere more or less, according to their position, their distance, and the state of the weather. To express this distinction, recourse must be had to an under tint, except where the tone is decidedly blue--an uncommon case. No mixture can give this with such truth as the neutral orange. A wash, therefore, should be passed over the mountains, with nearly all yellow in the high lights, or in the gleams of sunshine, and, on the contrary, almost all brown madder for the shadows. These two degrees of tone must be run into each other while the drawing is wet. A beautiful and soft under tone will thus be given to receive the greys. 162. ORANGE, OR BURNT ROMAN OCHRE,