The sulphate of iron, put in a small crucible, and lightly calcined, produces a suitable red oxide. Those which have the desired tone are selected. All the flesh reds are made in this way, and vary only in the degree of heat which they receive. 248. HAIR BROWN Yellow ochre, No. 244, 15 parts; oxide of cobalt, 1 part; well triturated and calcined, in order to give the tone to it. 249. LIVER BROWN Oxide of iron made of a red brown, and mixed with three times its weight of flux No. 2. A tenth of sienna earth is added to it if it is not sufficiently deep. 250. WHITE The white enamel of commerce in cakes. 251. YELLOWISH GREY Yellow No. 252, 1 part; blue No. 233, 1 part; oxide of zinc, 2 or 3 parts; flux No. 2, 5 parts; sometimes a little black is added, according to the tone which the mixture produces. The proportions of the blue and yellow vary. 252. YELLOW FOR BROWNS & GREENS Antimonic acid, 2 parts; sulphate of iron 1 part; flux No. 1, 9 parts. This colour is melted and sometimes a little Naples Yellow is added if it is too soft, i.e., melts too easily. 253. BLUEISH GREY FOR MIXTURES Blue previously made by melting together three parts of flux No. 1, and one part of the mixture of oxide of cobalt, 8 parts; oxide of zinc, 1 part; sulphate of iron calcined at a forge heat, 1 part; flux No. 2, 3 parts; triturate and add a little manganese in order to render it more grey. 254. GRAYISH BLACK FOR MIXTURES Yellow ochre, No. 244, 15 parts; oxide of cobalt, 1 part; triturate and calcine in a crucible until it has the desired tone. A little oxide of manganese is added in order to make it blacker; sometimes a little more of oxide of cobalt. 255. DEEP BLACK Oxide of cobalt, 2 parts; oxide of copper, 2 parts; oxide of manganese, 1 part; flux No. 1, 6 parts; fused borax, 1/2 part; melt and add oxide of manganese, 1 part; oxide of copper, 2 parts; triturate without melting. 256. GENERAL DIRECTIONS