The quality of it varies very much. It pre sents a splendid field for the enterprising adul terator. To find out if it is pure, put a portion on a hot metal plate, and hold it over a flame. If genuine, it will practically disappear when suffi ciently heated; the extent of the adulteration will be apparent by the amount which remains. It is seldom in much request for house painting in its full strength, being too vivid and being also very heavy. Vermilion, however, is very useful for obtaining, with white, pure and clean pink and similar delicate tints, which are per manent; if required in its full brilliancy, vermil ion stands best with, and applied in, good oil varnish alone. Imitation verminous are made from orange lead colored with eosin (a dye stuff). Crimson tones are obtained by admixture with white lead, zinc white, sulphate of lead, etc. Cheap colors are made from red lead and barytes.
Siennas are in their nature much the same as others, but contain more iron in their composi tion. They possess in a high degree the nature of getting brighter and yellower by age and ex posure. They have a greater staining power than ocher, and are slow in drying.
Burnt Sienna. Although coming more under the heading of red pigments, by reason of its bright, if impure, orange-red, this is, as its name implies, a burnt preparation of the mother pig ment. By the latter process it gains also in transparency and staining power, and it is really indispensable when graining some kinds of wood. It is obtained by baking the raw sienna till it becomes a rich orange-brown, with great transparency and depth of color. It has all the excellent qualities of ocher and raw sienna, with this addition—that it dries a little quicker.
Terra di Sienna, or Raw Sienna, is a very useful pigment. Although not so clean and bright in yellow as good ocher, it has more staining power when used with white, with which it forms very soft and agreeable cream tints and the so-called ivory whites so much in demand of late years. It is obtainable ready ground both in oil or in water, is equally serviceable in either case, and is reasonable in price. For the imita tion of maple, satinwood, pitch pine, etc., it is very popular and useful, prepared in water, while its semi-transparent nature renders it val uable where transparent effects are desired in oil painting processes.
Terra Vert is a silicate earth, permanent and slightly transparent either in oil or water. It
is used extensively for the peculiar tone of flesh needed in painting figures, because of its neutral tone.
The Umbers contain iron and manganese; they are useful colors, containing all the virtues and all the usefulness possible. The most com mon is usually termed raw umber—a natural ocher, found almost all over the world. The best is Turkey umber; and this, after burning, which makes it richer and warmer—when it is known as burnt umber—is one of the most useful pig ments. For graining, it is almost indispensable; and for all general purposes of painters' and paper-stainers' work it is one of the most valu able aids to soft and modest coloring, both in oil and water processes.
Whiting is carbonate of lime; it should be used only with the earth pigments, as it has a tendency to destroy vegetable colors. Prussian blue, Brunswick, and the cochineal lakes, and most of the yellows are of little use when mixed with whiting. Ochers, umbers, siennas, blue black, Venetian and Indian red, vermilion, mad der, and most of the blues, are useful with whit ing. It is the pigment which is used for wall pa pers, so that there should not be any difficulty in getting an extensive range of colors to go with it, as the number of tones used in wall papers is unlimited.
White Lead—white oxide of lead—is mixed with almost all other colors, sometimes to their detriment. It is very durable, and is, in conse quence, a good preservative; it is the strongest of all whites in opacity or covering power. When genuine, and properly prepared for use, it is a very reliable agent in obtaining a successfully painted surface which, under fair conditions, maintains its color and is impervious to water for a great number of years. Now for its disad vantages. It is highly poisonous, but the poison is very eccentric in its effect. The health of some people is not at all injured by its use, while that of others is affected by the slightest contact with it. Food should not be eaten in the presence of lead, especially when it is in the process of evap oration. When using lead, painters should take as much oil before going to bed as they can digest —a teaspoonful or less. Of course, the utmost cleanliness is very necessary. The acid of fruit helps to check the deleterious action of lead. An acid drink is an excellent antidote. Citric acid, acetic acid in water and drink made from lem ons, are very good.