B E 



are pure silica, crystallized in six- 

 sided prisms, terminated by six- 

 sided pyramids. 



BROME. | (from fipw/jios, odour, Gr.) 



BRO'HINE. j A simple, or element- 

 ary substance, being non-metallic. 

 Bromine exists in sea water, either 

 as bromine of sodium or bromine 

 of magnesium ; it was discovered 

 in 1826 by M. Balard, of Montpel- 

 lier. At common temperatures it 

 is liquid, of a dark red colour by 

 reflected, of a hyacinth- red by 

 transmitted light. At 116 Fah. 

 it boils ; between Fah. and 4 

 it congeals. The density of its gas 

 is 5-54 ; its equivalent 126-3 ; its 

 symbol Br. It acts powerfully on 

 animal substances, and is extremely 

 poisonous. It unites with all the 

 simple bodies, and with the metals, 

 forming, with the latter, a class of 

 compounds called bromides. Phil- 

 lips. Bromine has obtained its 

 name from its powerful and un- 

 pleasant smell ; its odour is suffo- 

 cating, and its taste pungent. 



BRO'NTIA. (from ppovrrj, Gr. thunder, 

 from its being supposed that these 

 fossils were thrown to the earth by 

 thunder.) A fossil echinite of the 

 family Cidaris. 



BRO'NZITE. A mineral called by 

 Werner Blattriger anthophyllite, 

 and by Haiiy Diallage metalloide. 

 It has a yellowish brown colour, 

 with a semi-metallic lustre. It is 

 found in serpentine, in Shetland 

 and in Upper Styria, and in green- 

 stone in many other places. Ac- 

 cording to Klaproth, it consists of, 

 silica 60; magnesia 27'5; oxide 

 of iron 10*5 ; water 0'5. Hard- 

 ness = 4 5. Specific gravity = 

 3 3-3. 



BROWN-COAL. A fresh-water forma- 

 of the tertiary series, but to which 

 sub- division of the tertiary period 

 it may belong is considered un- 

 certain by Sir C. Lyell, from the 

 extreme rarity of shells found in it. 

 Professor Buckland states, " In 



[ 61 ] B K 



some parts of Germany this brown- 

 coal occurs in strata of more than 

 thirty feet in thickness, chiefly 

 composed of trees which have been 

 drifted, apparently by fresh water, 

 from their place of growth, and 

 spread forth in beds, usually 

 alternating with sand and clay, at 

 the bottom of then existing lakes 

 or estuaries." The varieties of 

 wood found in the brown coal 

 strata are said to belong entirely to 

 dicotyledonous trees; but among 

 the impressions of leaves some have 

 been referred to a palm, by Prof. 

 Lindley, and others resemble the 

 Annamomum dulce, and Podocarpus 

 macrophylla, all indicating a warm 

 climate. 



" The place in the series of the 

 supracretaceous rocks," says Sir H. 

 de la Beche, " to which the brown 

 coal formation of Germany should 

 be referred, does not appear to be 

 as yet well determined. This 

 deposit is characterized by an 

 immense quantity of vegetable 

 remains, and is probably of differ- 

 ent ages. The brown-coal may be 

 traced from the environs of Aix-Ia- 

 Chapelle to the Ehine. It there 

 occurs in a narrow plateau between 

 the latter and the Erst, and acquires 

 a thickness of above 100 feet 

 between Bonn and Cologne, without 

 any extraneous bed. The brown- 

 coal deposit rests on the declivity 

 of the grauwacke mountains on the 

 right bank of the Ehine, and is 

 connected with the trachytic con- 

 glomerates and basaltic formations 

 of the Siebengebirge. It extends 

 to the country around Leipsic, to 

 the Elbe as far as Eorgan, and 

 occurs frequently in the low tracts 

 between Magdeburg and the Hartz. 

 It is found in the level country 

 between the Elbe and the Oder. 

 It generally rests upon a compact 

 tenacious clay, and is covered by 

 large masses of sand." Geological 

 Manual. 



