by the admixture of lake or vermilion with Prussian blue. They may be treated as the other coloured grounds as regards the varnish vehicle.

Black grounds may be formed either from lamp black or ivory black, but ivory black is preferable to lamp black, and possibly carbon black or gas black to either. These may be always applied with the shellac varnish as a vehicle, and their upper or polishing coats may consist of common seed-lac varnish. But the best quality of ivory black ground in the best super black japan yields, after suitable stoving, a very excellent black indeed, the purity of tone of which may be improved by adding a little blue in the grinding.

Common black japan grounds on metal by means of heat are procured in the following manner: The surface to be japanned must be coated over with drying oil, and when it is moderately dry must be put into a stove of such heat as will change the oil black without burning it. The stove should not be too hot when the oil is put into it nor the heat increased too fast, either which error would make it blister, but the slower the heat is increased and the longer it is continued, provided it be restrained within a due degree, the harder will be the coat of japan. This kind of japan requires no polish, having received from the heat, when properly regulated, a sufficiently bright surface.

This beautiful ground, produced by heat, is valued not only for its hardness and its capacity to stand a heat greater than that of boiling water, but also for its fine appearance. It is made by means of a varnish prepared thus: Take one gallon of good linseed oil and half a pound of umber, boil them together until the oil becomes very brown and thick, strain it then through a coarse cloth and set it again to boil, in which state it must be continued until it acquires a consistency resembling that of pitch; it will then be fit for use. Having thus prepared the varnish, clean well the surface which is to be japanned; then apply vermilion ground in shellac varnish or with drying oil, very thinly diluted with oil of turpentine, on the places intended to imitate the more transparent parts of the tortoise-shell. When the vermilion is dry, brush the whole over with the black varnish thinned to the right consistency with oil of turpentine. When set and firm put the work into a stove where it may undergo a very strong heat, which must be continued a considerable time, for three weeks or even a month so much the better. This ground may be decorated with painting and gilding in the same way as any other varnished surface, which had best be done after the ground has been hardened, but it is well to give a second annealing at a very gentle heat after it has been finished. A very good black japan may be made by mixing a little japan gold size with ivory or lamp-black, this will develop a good gloss without requiring to be varnished afterwards.

Japan work should be painted with real "enamel paints," that is with paints actually ground in varnish, and in that case all pigments may be used and the peculiar disadvantages, which attend several pigments with respect to oil or water, cease with this class of vehicle, for they are secured by it when properly handled from the least danger of changing or fading. The preparation of pigments for this purpose consists in bringing them to a due state of fineness by grinding them on a stone with turpentine. The best varnish for binding and preserving the pigments is shellac. This, when judiciously handled, gives such a firmness and hardness to the work that, if it be afterwards further secured with a moderately thick coat of seed-lac varnish, it will be almost as hard and durable as glass. The method of painting in varnish is, however, far more tedious than with an oil or water vehicle. It is, therefore, now very usual in japan work for the sake of dispatch, and in some cases in order to be able to use the pencil (brush) more freely, to apply the colours in an oil vehicle well diluted with turps. This oil (or japanners' gold size) may be made thus: Take 1 lb. of linseed oil and 4 oz. of gum anime, set the oil in a proper vessel and then add the gum anime powder, stirring it well until the whole is mixed with the oil. Let the mixture continue to boil until it appears of a thick consistence, then strain the whole through a coarse cloth and keep it for use. The pigments are also sometimes applied in a gum-water vehicle, but work so done, it has been urged, is not nearly so durable as that done in varnish or oil. However, those who formerly condemned the practice of japanning water-coloured decorations allowed that amateurs, who practised japanning for their amusement only and thus might not find it convenient to stock the necessary preparations for the other methods, might paint with water-colours. If the pigments are ground in an aqueous vehicle of strong isinglass size and honey instead of gum water the work would not be much inferior to that executed with other vehicles. Water-colours are sometimes applied on a ground of gold after the style of other paintings, and sometimes so as to produce an embossed effect. The pigments in this style of painting are ground in a vehicle of isinglass size corrected with honey or sugar-candy. The body with which the embossed work is raised is best formed of strong gum water thickened to a proper consistency with armenian bole and whiting in equal parts, which, being laid on in the proper figures and repaired when dry, may be then painted with the intended pigments in the vehicle of isinglass size or in the general manner with shellac varnish. As to the comparative value of pigments ground in water and ground in oil, that is between oil-colours and water-colours in enamelling and japanning, there seems to have been a change of opinion for some time back, especially as regards the enamelling of slate. The marbling of slate (to be enamelled) in water-colours is a process which Mr. Dickson says well repays study. It is greatly developed in France and Germany. The process is a quick one and the pigments are said to stand well and to maintain their pristine hue, yet if many strikingly natural effects result from the use of this process, its use has not spread in Great Britain, being confined wholly and solely to the marbling of slate (except in the case of wall-paper which is water-marbled in a somewhat similar way).

"In painting in oil-colour," says Mr. Dickson, "the craftsman trusts largely to his badger-hair brush to produce his effects of softness and marbly appearance; but in painting in water-colours, this softness, depth, and marbly appearance are produced mostly by the colour placed upon the surface, and left entirely untouched by badger or any other brush. The colour drying quickly, does not allow much time for working, and when dry it cannot be touched without spoiling the whole of the work. The difference first of all between painting in water and in oil colour, is that a peculiar grain exists with painting in water that it is absolutely impossible to get in oil. The charm of a marble is, I think, its translucency as much as its beautiful colour; it is to that translucency (for in marble fixed we have no transparency) that it owes its softness of effect, which makes marble of such decorative value. This translucency can only be obtained by thin glazes of colour, by which means each succeeding glaze only partly covers the previous one, the character of the marble being thus produced. This is done sometimes in oil-colour in a marvellous manner, but even the best of oil-painting in marble cannot stand the comparison of water-colour, and it is only by comparison that any accurate judgment can be formed of any work.