The modern Brunswick greens, which are made in a variety of shades, and sometimes known as chrome greens, Prussian greens, Victoria greens, and by other fancy names, really consist of a white pigment as a basis--usually sulphate of baryta (barytes), but occasionally also sulphate of lime (gypsum) and sulphate of lead--coloured green of varying intensity and depth by addition of a blue pigment in the shape of Prussian blue, and a yellow in the guise of chrome-yellow. There are what may be called four distinct standard shades recognised by colour-makers, viz. “pale,” “medium,” “deep,” and “extra deep”; but inasmuch as every manufacturer adopts a formula of his own, there may be appreciable differences among colours of the same nominal standard if by different makers. Taken as a whole, about three-fourths of their total weight consists of the foundation white pigment, usually barytes; about 1 to 6 per cent. is Prussian blue, according to the shade; and 14 to 18 per cent. chrome yellow; but there are brands occasionally met with which depart considerably from these average figures. The actual ingredients employed to form these green pigments are essentially different, according as the wet or the dry method of combining them be adopted. In selecting the various ingredients the following points must be borne in mind. The Prussian blue of every maker is not the same in quality, and while the character of the blue is not of the foremost importance when dark greens are being made, for light shades of green, on the other hand, it is essential to select only the best and brightest brands. In the same way the tint and quality of the chrome yellow are liable to considerable fluctuation, and it is almost impossible to ensure two lots having exactly the same characteristics, consequently the only way in which a certain shade of green can be ensured is by experimental trial with small quantities for each batch. Middle chromes can be used for deep greens, but only the lemon chromes for pale shades. Regarding the barytes which forms the basis of the pigment, there are no special precautions to be observed; and the same may be said of the gypsum, should that be adopted as a substitute for the barytes, except that 1 part by weight of gypsum takes the place of about 2½ parts of barytes. The latter, however, is much the more commonly used. For the dry method of compounding Brunswick greens, the above named ingredients are all that are required.