This section is from the book "Chromatography; Or, A Treatise On Colours And Pigments, And Of Their Powers In Painting", by George Field. Also available from Amazon: Chromatography, or A Treatise on Colours and Pigments, and of Their Powers in Painting.
Black Lead, Plumbago, Or Graphite, is a native carburet of iron or oxide of carbon, found in many countries, but nowhere more abundantly, or so fine in quality, as at Borrodale in Cumberland, where there are mines of it, from which the best is obtained, and consumed in large quantity in the formation of crayons and the black-lead pencils of the shops, which are in universal use in writing, sketching, designing, and drawing; for which the facility with which it may be rubbed out by Indian rubber, caoutchouc, or gum elastic, and the crumb of bread, admirably adapts it *.
Although not acknowledged as a pigment, its powers in this respect claim a place for it, at least among water-colours; in which way, levigated in gum-water in the ordinary manner, it may be used effectually with rapidity and freedom in the shading and finishing of pencil drawings, etc, and as a substitute therein for Indian ink. Even in oil it may be useful occasionally, as it possesses remarkably the property of covering, forms very pure grey tints, dries quickly, injures no colour chemically, and endures for ever. These qualities render it the most eligible black for adding to white in minute quantity to preserve the neutrality of its tint.
* Drawings, etc. in pencil are sometimes required to be fixed. This is best and most easily dune with water-starch, prepared in the manner of the laundress, of such strength as just to form a jelly when cold, which may be then applied with a broad camel's-hair brush, as in varnishing. The same may be done with thin, cold isinglass size, or rice-water; but these contract and cockle.
Although plumbago has usurped the name of Black Lead, there is another substance more properly entitled to this appellation, and which may also be safely employed in the same manner, and with like effects as a pigment. This substance is the Sulphuret of Lead, either prepared artificially, or as found native in the beautiful lead ore, or Galena, of Derbyshire.