Although plumbago has usurped the name of Black Lead, there is another substance more properly entitled to this appellation, and which may be used in the same way, and with like effects as a pigment. This substance is the sulphide of lead, found native in the beautiful lead ore, or Galena, of Derbyshire. An artificial sulphide can be prepared by dry and wet processes, which is subject to gradual oxidation on exposure to the air, and consequent conversion into grey or white. Neither variety can be compared to graphite for permanence, although the native is preferable to the artificial. Plumbago, or the so-called Black Lead, is often adulterated to an enormous extent with lamp black. 290. BLUE BLACK, _Charcoal_, _Liege_, or _Vine Black_, is a well-burnt and levigated charcoal prepared from vine twigs, of weaker body than ivory or lamp black, and consequently better suited to the grays and general mixed tints of landscape painting, in which it is not so likely to look black and sooty as the others may do. Of a cool neutral tint, it has, in common with all carbonaceous blacks, a preserving influence on white when duly mixed therewith; which it owes, chemically, to the bleaching power of carbon, and, chromatically, to the neutralizing and contrasting power of black with white. Compounded slightly with blue black, and washed over with zinc white, white lead may be exposed to any ordinary impure atmosphere with comparative impunity. It would be well for art if carbon had a like power upon the colour of oils, but of this it is deficient; and although chlorine destroys their colour temporarily, they re-acquire it at no very distant period. Alone, blue black is useful as a cool shade for white draperies; and compounded with cobalt, affords a good gray for louring clouds. 291. BRITISH INK is a compound black, preferred by some artists to Indian ink, on account of its not being liable to wash streaky, as the latter does: at the same time it is not so perfectly fixed on the paper as Indian ink. 292. INDIAN INK,