or Almond Black, made by burning the stones of fruits, the shell of the cocoa-nut, &c., is a violet-black, once much used by Parisian artists. Bouvier believes it to be a good black, but at the same time sensibly asks, of what use is it to have a black of this cast, which can always be given by lake, without diminishing but rather increasing the intensity of the black it may be mixed with. 305. _Prussian Black._ The same Prussian blue which gives a brown when burnt in the open air, yields a black when calcined in a close crucible. Very intense, very soft and velvety, and very agreeable to work, this bluish-black dries much more promptly than most other blacks, and scarcely requires grinding. On account of its extreme division, however, it would probably be found more energetic as a decolourising agent in admixture with organic pigments than most carbonaceous blacks. Another Prussian black, containing copper, and made by a wet process, is obtained when a dilute solution of cupric sulphate and ferrous sulphate, in proper proportions, is mixed with a quantity of ferrocyanide of potassium not in excess. A very bulky deep black precipitate is formed, which is difficult to wash, and is deep black when dry. It is insoluble in water, and appears to be a compound analogous to Prussian blue. As a pigment, this black is inferior to the preceding. 306. _Purple Black_ is, or rather was, a preparation of madder, of a deep purple hue approaching black. Powerful and very transparent, it glazed and dried well in oil, and was a durable and eligible pigment. Its tints with white lead were of a purple cast. 307. _Spanish Black_, or Cork Black, is a soft black, obtained by charring cork, and differs not essentially from Frankfort black, except in being of a lighter and softer texture. "Some of my friends," says Bouvier, "call it _Beggars' Ultramarine_, because it produces, by combinations, tints almost as fine as ultramarine." A blue but not a velvet black, where intensity is required some other is to be preferred. For mixtures, however, it is stated to be admirable, and especially for linen, skies, distances, and the various broken tints of carnations, &c. * * * * * Besides those blacks which have been mentioned, there are others furnished by several of the metals and by many organic substances employed as dyes; but as the blacks in common use are all permanent, and have been found sufficient for every purpose, it is scarce needful to swell the list. Nor is it more needful, the Editor considers, to swell the book; lest his aim be defeated of reflecting in a _moderate_-sized mirror the palette as it is and might be at the present day. Arrived at age, as it were, in its twenty-first chapter, this treatise may fitly conclude with Black, the last of the series of colours. Let us hope the maxim of Sir Joshua Reynolds, that success in some degree was never denied to earnest work may apply here.