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