pant, a protective or decorative covering for wood, iron, and other surfaces. An outdoor paint consists essentially of a drying oil mixed with a pigment. The latter is a finely ground, earthy substance to give body and color. Both the oil and the mineral must be waterproof. They must be insoluble in water. For inside work protected from rain, the liquid may be water containing gum or a size made of glue. The oil used most frequently is linseed oil pressed from flax seed. It resists weather, it adheres to surfaces, and it dries out, forming a hard, finished surface,-the three important qualities. Bean oil, produced in Manchuria, is used in Japan as a substitute for linseed oil. The same oil may be used for all colors, as color is given to paint by particles of mineral pigment held in the oil. It is interesting to know that paint has no color of its own. All are dark at night. All the colors of the rainbow are in the everyday white light of the sun. Each pigment has the faculty of absorbing all the colors but one. This one it reflects back to the eye of the observer. Thus a red barn in the landscape absorbs all the rays except the red; these it sends back to the eye. Pigments made of lead, zinc, or gypsum (lime), reject nearly all the rays of light and turn them back to the observer. They make white paints. White lead is the most important of all pigments. It is used not only for white paints, but for the body of other paints, the desired color being secured by the addition of a small quantity of some intense pigment. Green paint is made usually by the addition of copper, arsenic, or chrome green. Green paint and green wall paper run a chance of being poisonous. A blue pigment of great beauty may be made from the mineral, lapis lazuli, but is too expensive. An artificial ultra marine, as it is called, is made by mixing together fine clay and salt, which are white, charcoal, which is black, and sulphur, which is yellow. It is used chiefly for inside decoration. Prussian blue is prepared from iron and copper. Cobalt gives an intense blue. Indigo is used as a dye in water colors, but it washes out of a paint and is not suitable for outside work. Yellow paint usually contains ochre, a natural yellow clay. Its desirable qualities of freedom from grit, of weathering well, and of cheapness, are offset by a want of attractiveness. Chrome yellows are made by combining chromium with zinc or lead or barium. Red paint is the most common perhaps of all. Red pigments are usually lead tetroxide, that is to say, a red rust of lead; or else, and more commonly, a yellow ochre roasted in fire like a brick to bring out the trace of red-producing iron usually present. It is afterward crushed and ground to powder. Vermilion is a heavy, brilliant pigment manufactured from mercury and sulphur. The Chinese make a vermilion paint of superior quality, the preparation of which they long kept secret. Brown pigments are chiefly ochre, containing considerable manganese. Black paint has a body of charcoal in some form, usually lampblack. For inside woodwork, oil finish without a coloring pigment brings out the natural grain of the wood, and is much more artistic than paint, which hides the beauty of the wood. For outside work, paint is indispensable. Well painted buildings last longer and give an air of thrift and prosperity. According to the twelfth census 419 American factories with 8,151 workmen and a yearly payroll of nearly $4,000,000 turned out paints to the value of $51,000,000. See OIL.