GREEN COLORS. Although every shade of green can be produced both in oil and water-colors, and also in dyeing, most of them are made by mixing the various yellow and blue materials in different proportions. The following are the green paints in use : Arsenical green, or Scheele's green, is an arsenite of copper, made by dissolving arsenious acid in a solution of potash, and adding it to a solution of sulphate of copper. A precipitate is formed. which is Scheele's green, or Hitis green.
Brunswick best is crude oxychloride of copper, but the kind commonly sold is a mixture of carbonate of copper and chalk, or pipe-clay. One shade of this mixture is sometimes called Bremen green.
Chrome green is a mixture of Prussian blue and chrome yellow.
Copper green is sometimes a natural product, but is more generally manufactured; it is the oxide or the carbonate of copper, and is sometimes called green bite or mountain green.
ErneraW green is an arsenite of copper, prepared by a different process to Scheele's green.
Prise or Friesland green is made with sulphate of copper and sal-ammoniac.
Gellart's or Gellert's green is amixture of cobalt blue, flowers of zinc, and chrome yellow.
Sap green—the juice of buck-thorn berries fermented for seven or eight days, after which a little alum is added; and when evaporated to a thick consistency, it is pressed into bladders, and hung up until entirely dry. It is chiefly employed in water-colors.
Seltweinfurth green is another form of the arsenite of copper produced by dissolving separately equal parts of acetate of copper and arsenious acid. The solutions are then added together quite hot, and the precipitate formed is the beautiful but highly danger ous pigment. Its great beauty has led to its frequent employment in coloring wall papers, artificial flowers, and even in some cases, it is to be feared, in coloring sugar con fections. • • All of these colors, with the exception of sap green are dangerously poisonous.
Green, in dyeing, is always understood to be a mixture of the two colors blue and yellow. The materials are generally mixed first with blue, and afterwards with yellow, proportioning the intensity of each to the shade of color required.
The Chinese have a vegetable green color called lult•kao, or green indigo, but it is exceedingly costly, and is only obtainable in very small quantities.