There are many shades or varieof this colour. The native black substances are, black chalk, pitcoal, black sands, black vege-table juices, and cuttle-fish ink. Those which are the product of lire, comprehend charcoal blacks, soot blacks, and black metallic calces.
Blacks obtained by mixture, are those from iron, silver, and from a combination of lead with sulphur. The infusions of certain vegetable astringents, mixed with green vitriol (which is a solution of iron in the sulphuric acid), produce a deep black colour, of most extensive use for dyeing and staining. The astringent substances chiefly employed for this purpose, are the excrescences of the oak-tree, called galls ; all parts of this tree, as the leaves, acorns, and more particularly the bark and wood. A great variety of other vegetable substances, such as the small branches and flowers of the sumach-tree, alder bark, bistort root, and, in genera!, those which are astringent or corrugating to the taste, possess similar properties. The power by which these vegetables strike black with vitriol, and their astringency, are proportional to one another, and seem to depend on one and the same principle. Of the other properties of this astringent and colouring mat-ter, little more is known, than that it is dissolved and extracted both by water and spirit of wine, and that it does not exhale on the evaporation of the menstruum.— See the article Dyking.
The only native vegetable black, is the juice of the cashew nut-tree, . or Anacurd'ium occidentals, which probably is the tree that yields the black varnish of China and Japan. -See vannish.