is extracted by watery solution from the soot of wood fires, whence it derives a strong pyroligneous scent. It is a very powerful citrine-brown, washes well, and has a clearness suited to architectural subjects. Its use is confined to water-colour painting, in which it was much employed by the old masters for tinting drawings and shading sketches, before the general application of Indian ink to such purposes. Of a wax-like texture, it is perfectly durable, but unfitted for oil, drying therein with the greatest difficulty. A substance of this kind collects at the back of fire-places in cottages where peat is the constant fuel burnt; which, purified by solution and evaporation, yields a fine bistre, similar to the Scotch. All kinds of bistre attract moisture from the atmosphere. 243. BONE BROWN and _Ivory Brown_ are obtained by roasting bone and ivory until by partial charring they become of a brown colour throughout. Though much esteemed by some artists, they are not quite eligible pigments, being bad driers in oil, the only vehicle in which they are now used. Moreover, their lighter shades are not permanent either in water or oil when exposed to the action of strong light, or mixed in tint with white lead. The palest of these colours are the most opaque: the deepest are more durable, and most so when approaching black. Neither bone nor ivory brown is often employed, but the former may be occasionally applied in forming clear, silvery, warm grays, in combination with zinc white. 244. BURNT UMBER is what its name denotes, and has a deeper shade with a more russet hue than the raw umber. A quiet brown, it affords clear and warm shadows, but is apt to look rather turbid if used in great depth. It washes and works capitally in water, and dries quickly in oil, in which it is employed as a siccative. Perfectly stable in either vehicle, it may sometimes be substituted for Vandyke brown, is eligible in fresco, and invaluable in buildings. Where the lakes of madder require saddening, the addition of burnt umber increases their powers, and improves their drying in oil. It contains manganese and iron, and may be produced artificially. The old Italians called it _falsalo_. 245. CALEDONIAN BROWN is a permanent native pigment, the use of which is confined to oil. A magnificent orange-russet brown of considerable transparency, it is marked by great depth and richness, and will be found serviceable where a powerful brown of the burnt Sienna class is required. 246. CAPPAH BROWN, or _Cappagh Brown_, is likewise a colour peculiar to oil. It is a species of bog-earth or peat, mixed with manganese in various proportions, and found on the estate of Lord Audley at Cappagh, near Cork. The specimens in which the peat earth most abounds are of light weight, friable texture, and dark colour; while those which contain more of the metal are heavy and paler.