Terre De Cassel Or Corruptly Castle Earth Is Specially An Oil

: ON THE SEMI-NEUTRAL, BROWN.

pigment, similar to burnt umber but of a more russet hue. It is an earth

containing bitumen, a substance which, with pit-coal, lignite or brown

coal, jet, petroleum or rock oil, naphtha, &c., is looked upon as a

product of the decomposition of organic matter, beneath the surface of

the earth, in situations where the conditions of contact with water, and

almost total exclusion of atmospheric air, are fulfilled. Deposited at
/> the bottom of seas, lakes, or rivers, and subsequently covered up by

accumulations of clay and sand, the organic tissue undergoes a kind of

fermentation by which the bodies in question are slowly produced. The

true bitumens appear to have arisen from coal or lignite by the action

of subterranean heat; and very closely resemble some of the products

yielded by the destructive distillation of those bodies.



Rich as is the tone of colour of Cassel earth, it is apt to lose this in

some measure on exposure to light. Merimee remembers to have seen a

head, the brown hair of which had been painted partly with the earth

alone, and partly with a mixture of the earth and white; yet the hair

where the white was employed was darker than that painted solely with

the brown, the white having fixed the colour. To compensate for its

thus fading, it should be mixed with pigments that are permanent, such

as umber and lamp black. Like all bituminous earths, it needs the

strongest drying oil. By calcination, a greater degree of intensity may

be imparted to the colour, and perhaps a little more solidity. In

landscapes it is of much service for the most vigorous portions of

foregrounds and the trunks of trees, as well as for painting cavernous

rocks or deep recesses in architecture. Compounded with burnt lake and a

little Prussian blue, it gives a black the most profound.



TTITLE CHALON'S BROWN



is a water-colour pigment, transparent and inclining to red; deep, full,

and very rich. On exposure to light it becomes less russet, but is

otherwise strictly stable.



TTITLE COLOGNE EARTH,



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