431 



BIROSTRITES. 



BISON. 



1*2 



There are specimens in the British Museum. There is only one 

 species of this genus. 



y 



Purse-Crab (Biryut Latro.) 



BIROSTRI'TES, a genus of Fossil Mollutca named by Lamarck. 

 He has placed it under his family Jiudittes, a family which, as Mr. O. 

 Sowerby observes, might be struck out ; for there can be hardly any 

 doubt that Lamarck has misconceived or misplaced the genera of 

 which it is composed. G. Sowerby, from an examination of the cast 

 of the inside of the shell, expresses his conviction that Birostrites 

 ought to be placed next to Dicerat, or at least in the same family with 

 C'hama and IKceras, inasmuch as it accords very nearly with those 

 shells in its internal characters. Rang has placed the genera Batolites, 

 l!'i r hfiiiislet, and Amplexus, near to this genus. 



The following is Lamarck's description of this singular fossil : Shell 

 composed of two pieces or valves, which do not unite by the edges of 

 their base, one enveloping the other, and the dorsal disc of each being 

 elevated into a nearly straight cone slightly arched within. These 

 horn-shaped valves are unequal, and diverge obliquely under the form 

 of a very open V. It seems as if one valve came out of the base of 

 the other, and it is always the shortest that is enveloped. Birostrites 

 inrerjuilfibus is the only species which Lamarck records. 



BIRTHWORTS. [ARISTOLOCHIACE.E.] 



BISH. [BiKH.] 



BISMORE, a name given in the Orkneys to the 15-spined Stickle- 

 back, [GASTEBOSTEUS.] 



BISMUTH, a metal that was unknown to the ancients. It was 

 referred to by Agricola in his work on mining in 1529, and was subse- 

 quently described by Stahl and Dufay. 



The minerals in which this metal constitutes the principal ingredient 

 are comparatively few in number ; and of these only two species are of 

 any importance in a commercial point of view, namely, the native 

 bismuth, and its sulphurets. The general characters of these 

 minerals are the following. Before the blow-pipe they are readily 

 and reduced to a metallic state, the regulus itself gradually 

 Huliliming if the flame be continued, leaving on the charcoal an 

 orange-yellow areola, which however may readily be made to disappear 

 in the deoxidising flame. When the metallic regulus is fused in an 

 open glass tube, a yellowish-white sublimate is obtained, and the 

 regulus itself becomes covered by the fused oxide, which while hot is 

 of a dark brown colour but assumes a yellow tint on cooling. These 

 minerals are all of them soluble in strong nitric acid, the solution 

 yielding a white precipitate on being dropped into water. They are 

 known and described by mineralogists under the following names : 

 Native or Octahedral Bismuth, Bismuth-Ochre, Prismatic Bumuth- 

 i.hniiT, Needle-Ore or Acicular Bismuth-Glance, called by Phillips 

 Plumbo- Cupriferous Sulphuret of Bismuth, TeUwbimutli, formerly 

 known by the name of Molybdan Silver. 



Native or Octahedral Bitmuth is sometimes found crystallised : the 

 observed forms are the octahedron, the tetrahedron, and combinations 

 of the latter with the dodecahedron, which produce the shape seen 

 in the accompanying figure. 



The faces marked o belong to the tetrahedron and those marked 

 with d to the rhombic dodecahedron. The edge between the faces o 

 is therefore 70" 32', between the faces d 120, and in the edges of com- 

 bination between o and d 144 44'. These crystals are generally very 



HAT. HIST. DIV. VOL. I. 



imperfect, and the faces rough and uneven ; they possess a perfect 



cleavage parallel to the faces of the octahedron. The hardness varies 



from 2 to 2'5, the specific gravity from 9'6 to 



9'8. The crystals are opaque, possess the 



metallic lustre, and the fresh fracture presents 



a reddish silver white; but the surface is 



usually tarnished, owing to partial oxidation, 



and presents a variegated appearance of gray, 



red, and blue colours. They may be considered 



as presenting us with the metal Bismuth in 



a pure state, the only foreign matter being 



traces of arsenic. The occurrence of crystals is 



somewhat rare, this mineral being usually found in feathery and 



arborescent forms, and also in dentiform concretions in veins, traversing 



gneiss, mica, and clay-slates, where it is usually accompanied by ores 



of silver, cobalt, nickel, and iron. It is found at St. Colomb and 



Botallack mines in Cornwall, and at CUstle-Carrock in Cumberland, but 



in much greater abundance in the mines of Saxony and Bohemia, at 



Johann-Georgenstadt, Annaberg, Altenberg, Schneeberg, and at 



Joachimsthal, from whence the greater portion of the Bismuth of 



commerce is obtained. It is also found at Beiber in Hainau, at 



Loling in Carinthia, and in the Sophia mine at Witticheu in 



Fiirstenberg. 



The Bismuth-Ochre is a rare mineral, which occurs massive and 

 disseminated. It is of a straw-yellow, passing sometimes into a light 

 yellowish gray. Its specific gravity is 4'36, and its chemical 

 constitution 



Bismuth ...... 89'87 



Oxygen 10'13 



It usually contains small quantities of arsenic and oxide of iron as 

 impurities. Its known localities are St. Agnes, Cornwall ; Schneeberg 

 and Johann-Georgenstadt, in Saxony ; and Joachimsthal, in Bohemia. 



Bismuth-Glance, Bisniutite, a Carbonate of Bismuth, occurs in four- 

 sided prisms of unknown dimensions, but it is stated by Phillips to 

 have angles about 91 and 89. It is further characterised by its 

 metallic lustre, and lead-gray approaching steel-gray colour, and from 

 its possessing a perfect cleavage in the direction of the short diagonal, 

 and one less perfect in the direction of the base. According to Mohs 

 the hardness is between 2 and 2'5, and the specific gravity 6'549. It 

 also occurs massive of a granular composition, or columnar, the 

 individuals being long and straight, and aggregated in various 

 directions. According to the analysis of H. Rose of a specimen from 

 Reddarbyttan, it is thug composed : 



Sulphur . . . 18-49 . . . 1872 

 Bismuth .... 81-51 . . . . 80-98 



Before the blow-pipe sulphur is first driven off, which is followed 

 by a sublimate having the odour of tellurium, and afterwards 

 the characters are the same as those of the other minerals of 

 Bismuth. 



Bismuth-Blende is a Silicate of Bismuth. 



Other minerals in which Bismuth occurs are Needle-Ore and Tellur- 

 bismuth. Needle-Ore is also called Acicular Bismuth. It is a 

 sulphuret of bismuth, lead, and copper, containing a trace of gold. 

 It comes from Siberia. Ttllurbismuth, or Tetradymite, is composed of 

 tellurium and bismuth. It has a foliated structure, and a pale steel- 

 gray colour. It comes from Schemnitz, and also from Brazil. 



(Dana, Mineralogy.) 



BISON, the name of a genus of Ruminant Animals belonging to 

 the family Bovidce. The genus Biton comprehends two living species, 

 one of them European, now become very scarce and verging towards 

 extinction ; the other American, and, notwithstanding the advances 

 of man, still multitudinous. 



European Bison. 



As much difference of opinion has prevailed with regard to the 

 historical records and true characters of the first or European species 

 of Bison, we shall quote a few of the synonyms of this animal as 

 given in the Catalogue of the Specimens of Mammalia, in the British 

 Museum, by Dr. J. E. Gray. 



The Bison Aurochs, or European Bison, is the Bos Bison of 

 Linnaeus ; Biton Bonassus, Dr. J. E. Gray ; Bos Urui, Boddaert ; Bos 

 Biton Aurochs, Lesson; Boi Taurus Urus, Gmelin; Bos Bonassus, 

 Brisson ; Bison Europcms, Owen ; Bos Bison sea Bonassus, Wagner ; 

 Bison jubatus, Pliny ; Bison, Gesner, Aldrovandus, and Gilibert ; 

 Urus, Caesar; Aurochs, Cuvier, Buffon, and Desmoulins; Bonasus, 

 Pliny, Gesner, Klein, Buffon, and Ray. It is also the Urochs, 

 Auer-Ochse or Auer-Ochs, Wald-Ochse, Wilder Ochs, Berg-Ochs, 

 Buckel-Ochs, Afrikanischer Wilder Ochs, Preussischo und Lithanisehe 

 Auer-Ochs, Zurb, and Manistier, of various German writers. To these 

 various synonyms we may now add that of Bison pritciu of Owen, 

 as there is no doubt that the bones of the Great Fossil Aurochs 

 belong to the same species as those now living in the forests of 

 Lithuania. 



The difficulty of identifying this animal has arisen from the fact, 

 that besides the Bison there existed at one time in Europe and in 

 Great Britain a wild ox (Boiprimigenius), whose remains are numerous, 

 but which has undoubtedly become quite extinct. Pennant, in his 

 ' British Zoology,' after stating his belief that the ancient wild cattle 



2 I 



