Grey is the second and intermediate of the neutral colours, standing between _white_ and _black_. True or normal grey is only obtainable by admixture of pure white with pure black, various proportions of which afford numerous tones of pure grey. In practice it may likewise be produced by a thin wash of black over white. The neutral gr_e_y differs from the semi-neutral gr_a_y in not being coloured by any primary, secondary, tertiary, or semi-neutral; hence any blue, purple, olive, or gray added to it, at once destroys the neutrality of grey, and converts it into gray. Thus easily defiled and changed in class, grey is rather a theoretical than a practical colour. To our knowledge, there has never been a true grey pigment, that is, one composed exclusively of pure white and pure black; the gr_a_ys known to the palette as Mineral Grey and Payne's Grey having been incorrectly named. Practically, the nearest approach to a normal grey is furnished by Black Lead, which forms grey tints of greater permanence and purity than the blacks in general use, and is now employed for this purpose with approved satisfaction by experienced artists. Being compounded of white and black, grey partakes in some measure of the qualities of both those colours--for colours, as a matter of convenience, they must be called; although white is often spoken of as no colour, and black as the complete extinction of all colour. With white predominant, grey is used, pure or coloured, for the general lights of a picture; just as, with black predominant, grey is employed, pure or coloured, for the shades. It helps to subdue the absolute white, and to make the absolute black conspicuous. Black and white are in some respects complementary to each other, and when in contact, appear to differ more from each other than when viewed separately: both show with best effect when harmonised by a medium of grey, normal or otherwise. The primary colours, also, gain in brilliancy and purity by the proximity of grey. With dark colours, such as blue and violet, and deep tones in general, grey forms assortments of analogous harmonies; while with the luminous colours, such as red, orange, yellow, and the light tints of green, it forms harmonies of contrast. Although grey never produces a bad effect in its assortments with two luminous colours, in most cases the association is dull and inferior to black and white. The only instance in which grey associates with two such colours more happily than white is that with red and orange. Grey is inferior to both white and black with red and green, red and yellow, orange and yellow, orange and green, yellow and green; and is not so good as white with yellow and blue. In association with sombre colours, such as blue and violet, and with broken tones of luminous colours, grey gives rise to harmonies of analogy which have not the vigour of those with white; but if the colours do not combine well together, it has the advantage of separating them from each other.