Haerlem Blue Berlin Blue Mineral Blue Is A Lighter And

somewhat brighter Prussian blue, with less depth and less permanence. It

is a species of lake, having a considerable proportion of aluminous

base, to which its paler tint is due. As the stability of Prussian blue

rests in a great measure on the marvellous amount of latent colour the

pigment contains, when its particles of colour are set farther apart by

the intervention of the alumina, the permanence of its hue is

endangered. It was remarked, with respect to vitrified pigments, that

colour depends on cohesion. More or less, this holds good as regards all

pigments; but not only, as was also observed, does colour rest on

cohesion, in many instances durability depends likewise. It is only when

a colour is stable in itself that its particles will bear separating:

native ultramarine, for example, may be weakened almost to white, and

will still preserve its hue. If, however, a colour be naturally

fugitive, and rely chiefly on its extreme depth for what permanence it

possesses, that colour cannot with impunity be paled: witness the

cochineal lakes, which the deeper they are, the more durable they are

found; and so it is with Prussian blue. Antwerp blue is distinguished

from the latter by its more earthy fracture.



Gross And Material Which Is Content With Mere Nature And To Which Harmonizing Contrast Of Citrine Is A Deep Purple Which May Be Seen facebooktwittergoogle_plusredditpinterestlinkedinmail