Coassatio (from coasso, to join planks together). A general term for planks joined together, such as the flooring of a room, the top of a table, the deck of a ship, the roadway of a wooden bridge, &c. (See Constratum.)
Fig. 175. Coat Armour.
Fig. 176. Coat Armour. Devices on shield.
Coat Armour, Med. Embroidery of heraldic devices upon costume; hence a term for heraldry in general. (Figs. 175 and 176.)
Coat Cards, O. E. Court cards and tens, so named from the coat armour worn by the figures.
Cob. Irish name of a Spanish coin formerly current in Ireland; value about 4s. 8d.
Cobalt. A metal found in various combinations, from which various colouring matters are obtained of great use in the arts. Cobalt blue, a beautiful blue pigment, is obtained by mixing a salt of pure cobalt with a solution of pure alum, precipitating the liquid by an alkaline carbonate, washing the precipitate with care, drying and igniting it strongly. A fine green, known as Rinmann’s green, is similarly prepared. The chloride, the nitrate, and the sulphate of cobalt form sympathetic inks, which only become visible when the moisture is absorbed by the application of heat. From phosphate of cobalt a beautiful blue pigment is produced, called Thenard’s blue. It is said to have all the characters of ultramarine. Oxide of cobalt has the property of colouring glass blue; hence a glass formed of this oxide under the name of smalt is the blue colouring matter used for ornamenting porcelain and earthenware, for staining glass, for painting on enamel, &c.
Cobalt-bloom. (See Erythrine.)