BERYL. A beautiful mineral or gem, of moderate price, usually of a green colour of various shades, passing into honey-yellow and sky blue.
BEZOAR. The name of certain concretions found in the stomachs of animals, to which many fanciful virtues were formerly ascribed. They are interesting only to the chemical pathologist.
BILE. (Bile, Fr.; Galle, Germ.) The secreted liquor of the liver in animals. For an account of the uses of animal bile in the arts, see [Gall].
BIRDLIME. (Glu, Fr.; Vogelleim, Germ.) The best birdlime may be made from the middle bark of the holly, boiled seven or eight hours in water, till it is soft and tender, then laid by heaps in pits under ground, covered with stones after the water is drained from it. There it must be left during two or three weeks, to ferment in the summer season, and watered, if necessary, till it passes into a mucilaginous state. It is then to be pounded in a mortar to a paste, washed in running water, and kneaded till it be free from extraneous matters. It is next left for four or five days in earthen vessels to ferment and purify itself, when it is fit for use. Birdlime may be made by the same process from the mistletoe (viburnum lantana), young shoots of elder, and the barks of other vegetables, as well as from most parasite plants.
Good birdlime is of a greenish colour, and sour flavour, somewhat resembling that of linseed oil; gluey, stringy, and tenacious. By drying in the air it becomes brittle, and may be powdered; but its viscosity may be restored by moistening it. It has an acid reaction with litmus paper. It contains resin, mucilage, a little free acid, colouring and extractive matter. The resin has been called Viscine.
BISMUTH. (Bismuth, Fr.; Wismuth, Germ.) Called also marcasite and tin-glass. It was shown to be a metal somewhat different from lead, by G. Agricola, in 1546; Stahl and Dufay proved its peculiarity; but it was more minutely distinguished by Pott and Geoffroy, about the middle of the last century. It is a rare substance, occurring native, as an oxide, under the name of bismuth ochre; as a sulphuret, called bismuth glance; as a sulphuret with copper, called copper bismuth ore; as also with copper and lead, called needle ore. It is found associated likewise with selenium and tellurium. The native metal occurs in various forms and colours, as white, reddish, and variegated; in primitive and floetz formations, along with the ores of cobalt, nickel, copper, silver, and bismuth ochre; at the Saxon Erzgebirge, near Schneeberg, and Joh. Georgenstadt; also in Bohemia, Baden, Wurtemberg, Hessia, Sweden, Norway, England, and France.
The production of this metal is but a limited object of the smelting-works of the Saxon Erzgebirge at Schneeberg. It there occurs, mixed with cobalt speiss, in the proportion of about 7 per cent. upon the average, and is procured by means of a peculiar furnace of liquation, which is the most economical method, both as to saving fuel, and oxidisement of the bismuth.
The bismuth eliquation furnace at Schneeberg is represented in [figs. 112], [113], and [114.], of which the first is a view from above, the second a view in front, and the third a transverse section in the dotted line A B of [fig. 112.] a is the ash-pit; b, the fireplace; c, the eliquation pipes; d, the grate of masonry or brickwork, upon which the fuel is thrown through the fire-door e e. The anterior deeper lying orifice of the eliquation pipes is closed with the clay-plate f; which has beneath a small circular groove, through which the liquefied metal flows off. g is a wall extending from the hearth-sole nearly to the anterior orifices of the eliquation pipes, in which wall there are as many fire-holes, h, as there are pipes in the furnace; i are iron pans, which receive the fluid metal; h, a wooden water-trough, in which the bismuth is granulated and cooled; l, the posterior and higher lying apertures of the eliquation pipes, shut merely with a sheet-iron cover. The granulations of bismuth drained from the posterior openings fall upon the flat surfaces m, and then into the water-trough. n n are draught-holes in the vault between the two pipes, which serve for increasing or diminishing the heat at pleasure.