Page:EB1911 - Volume 04.djvu/24

 disulphide is a grey metallic substance, which is decomposed by hydrochloric acid with the separation of metallic bismuth and the formation of bismuth trichloride. Bismuth trisulphide, Bi2S3, constitutes the mineral bismuthite, and may be prepared by direct union of its constituents, or as a brown precipitate by passing sulphuretted hydrogen into a solution of a bismuth salt. It is easily soluble in nitric acid. When heated to 200° it assumes the crystalline form of bismuthite. Bismuth forms several oxysulphides: Bi4O3S constitutes the mineral karelinite found at the Zavodinski mine in the Altai; Bi6O3S4 and Bi2O3S have been prepared artificially. Bismuth also forms the sulphohaloids, BiSCl, BiSBr, BiSI, analogous to the oyxhaloids.

Bismuth sulphate, Bi2(SO4)3, is obtained as a white powder by dissolving the metal or sulphide in concentrated sulphuric acid. Water decomposes it, giving a basic salt, Bi2(SO4)(OH)4, which on heating gives (BiO)2SO4. Other basic salts are known.

Bismuth forms compounds similar to the trisulphide with the elements selenium and tellurium. The tritelluride constitutes the mineral tetradymite, Bi2Te3.

Analysis.—Traces of bismuth may be detected by treating the solution with excess of tartaric acid, potash and stannous chloride, a precipitate or dark coloration of bismuth oxide being formed even when only one part of bismuth is present in 20,000 of water. The blackish brown sulphide precipitated from bismuth salts by sulphuretted hydrogen is insoluble in ammonium sulphide, but is readily dissolved by nitric acid. The metal can be reduced by magnesium, zinc, cadmium, iron, tin, copper and substances like hypophosphorous acid from acid solutions or from alkaline ones by formaldehyde. In quantitative estimations it is generally weighed as oxide, after precipitation as sulphide or carbonate, or in the metallic form, reduced as above.

Pharmacology.—The salts of bismuth are feebly antiseptic. Taken internally the subnitrate, coming into contact with water, tends to decompose, gradually liberating nitric acid, one of the most powerful antiseptics. The physical properties of the powder also give it a mild astringent action. There are no remote actions.

Therapeutics.—The subnitrate of bismuth is invaluable in certain cases of dyspepsia, and still more notably so in diarrhoea. It owes its value to the decomposition described above, by means of which a powerful antiseptic action is safely and continuously exerted. There is hardly a safer drug. It may be given in drachm doses with impunity. It colours the faeces black owing to the formation of sulphide.

 BISMUTHITE, a somewhat rare mineral, consisting of bismuth trisulphide, Bi2S3. It crystallizes in the orthorhombic system and is isomorphous with stibnite (Sb2S3), which it closely resembles in appearance. It forms loose interlacing aggregates of acicular crystals without terminal faces (only in a single instance has a terminated crystal been observed), or as masses with a foliated or fibrous structure. An important character is the perfect cleavage in one direction parallel to the length of the needles. The colour is lead-grey inclining to tin-white and often with a yellowish or iridescent tarnish. The hardness is 2; specific gravity 6.4–6.5. Bismuthite occurs at several localities in Cornwall and Bolivia, often in association with native bismuth and tin-ores. Other localities are known; for instance, Brandy Gill in Caldbeck Fells, Cumberland, where with molybdenite and apatite it is embedded in white quartz. The mineral was known to A. Cronstedt in 1758, and was named bismuthine by F. S. Beudant in 1832. This name, which is also used in the forms bismuthite and bismuthinite, is rather unfortunate, since it is readily confused with bismite (bismuth oxide) and bismutite (basic bismuth carbonate), especially as the latter has also been used in the form bismuthite. The name bismuth-glance or bismutholamprite for the species under consideration is free from this objection.

 BISMYA, a group of ruin mounds, about 1 m. long and m. wide, consisting of a number of low ridges, nowhere exceeding 40 ft. in height, lying in the Jezireh, somewhat nearer to the Tigris than the Euphrates, about a day’s journey to the south-east of Nippur, a little below 32° N. and about 45° 40′ E. Excavations conducted here for six months, from Christmas of 1903 to June 1904, for the university of Chicago, by Dr Edgar J. Banks, proved that these mounds covered the site of the ancient city of Adab (Ud-Nun), hitherto known only from a brief mention of its name in the introduction to the Khammurabi code (c. 2250 ). The city was divided into two parts by a canal, on an island in which stood the temple, E-mach, with a ziggurat, or stage tower. It was evidently once a city of considerable importance, but deserted at a very early period, since the ruins found close to the surface of the mounds belong to Dungi and Ur Gur, kings of Ur in the earlier part of the third millennium Immediately below these, as at Nippur, were found the remains of Naram-Sin and Sar-gon, c. 3000 Below these there were still 35 ft. of stratified remains, constituting seven-eighths of the total depth of the ruins. Besides the remains of buildings, walls, graves, &c., Dr Banks discovered a large number of inscribed clay tablets of a very early period, bronze and stone tablets, bronze implements and the like. But the two most notable discoveries were a complete statue in white marble, apparently the most ancient yet found in Babylonia (now in the museum in Constantinople), bearing the inscription—“E-mach, King Da-udu, King of Ud-Nun”; and a temple refuse heap, consisting of great quantities of fragments of vases in marble, alabaster, onyx, porphyry and granite, some of which were inscribed, and others engraved and inlaid with ivory and precious stones.

 BISON, the name of the one existing species of European wild ox, Bos (Bison) bonasus, known in Russian as zubr. Together with the nearly allied New World animal known in Europe as the (North) American bison, but in its own country as “buffalo,” and scientifically as Bos (Bison) bison, the bison represents a group of the ox tribe distinguished from other species by the greater breadth and convexity of the forehead, superior length of limb, and the longer spinal processes of the dorsal vertebrae, which, with the powerful muscles attached for the support of the massive head, form a protuberance or hump on the shoulders. The bisons have also fourteen pairs of ribs, while the common ox has only thirteen. The forehead and neck of both species are covered with long, shaggy hair of a dark brown colour; and in winter the whole of the neck, shoulders and hump are similarly clothed, so as to form a curly, felted mane. This mane in the European species disappears in summer; but in the American bison it is to a considerable extent persistent.

The bison is now the largest European quadruped, measuring about 10 ft. long, exclusive of the tail, and standing nearly 6 ft. high. Formerly it was abundant throughout Europe, as is proved by the fossil remains of this or a closely allied form found on the continent and in England, associated with those of the extinct mammoth and rhinoceros. Caesar mentions the bison as abounding, along with the extinct aurochs or wild ox, in the forests of Germany and Belgium, where it appears to have been occasionally captured and afterwards exhibited alive in the Roman amphitheatres. At that period, and long after, it seems to have been common throughout central Europe, as we learn from the evidence of Herberstein in the 16th century. Nowadays bison are found in a truly wild condition only in the forests of the Caucasus, where they are specially protected by the Russian government. There is, however, a herd, somewhat in the condition of park-animals, in the forest of Byelovitsa, in Lithuania, where it is protected by the tsar, but nevertheless is gradually dying out. In 1862 the Lithuanian bisons numbered over 1200, but by 1872 they had diminished to 528, and in 1892 there were only 491. The prince of Pless has a small herd at Promnitz, his Silesian estate, founded by the gift of a bull and three cows by Alexander II. in 1855, his herd being the source of the menagerie supply.

Bison feed on a coarse aromatic grass, and browse on the leaves, shoots, bark and twigs of trees.

The American bison is distinguished from its European cousin by the following among other features: The hind-quarters are weaker and fall away more suddenly, while the withers are proportionately higher. Especially characteristic is the great mass of brown or blackish brown hair clothing the head, neck and forepart of the body. The shape of the skull and horns is also different; the horns themselves being shorter, thicker, blunter and more sharply curved, while the forehead of the skull is more convex and the sockets of the eyes are more distinctly tubular. This species formerly ranged over a third of North America in countless numbers, but is now practically extinct. The great herd was separated into a northern and