BOB, 



[ 57] 



B 11 



ore is familiar to the mineralogist. 

 From what source the iron is derived 

 is by no means obvious, since we 

 cannot in all cases suppose that it 

 has been precipitated from the 

 waters of mineral springs. It has 

 been suggested that iron, being 

 soluble in acids, may be diffused 

 through the whole mass of vege- 

 tables, when they decay in a bog, 

 and may, by its superior gravity, 

 sink to the bottom, and be there 

 precipitated, so as to form bog-iron 

 ore. Dr. Man tell observes, " the 

 formation of what is termed bog- 

 iron ore, found in marshes and peat 

 bogs, is supposed to have been 

 derived from the decomposition of 

 rocks over which water has flowed ; 

 but the observations of Ehrenberg, 

 seem to indicate a different ori- 

 gin." Ehrenberg discovered that 

 bog-iron consists of innumerable 

 articulated threads, of a yellow- 

 ochre colour, composed partly of 

 flint, and partly of oxide of iron ; 

 these threads being the cases of a 

 minute animalcule, termed Gaillon- 

 ella ferruginea. 



BOLE, (from PU)\O$. Gr.) A friable 

 clay, or earth, often highly coloured 

 with iron. It occurs in solid 

 amorphous masses of a yellow red, 

 or blackish-brown colour, or pitch 

 black; it is found in wacke, and 

 basalt, from the decomposition of 

 which it may arise. 



BOLE'TTTS. A genus of mushrooms, of 

 the order Eungi. 



BOLO'GNA STONE. ] A variety of sul- 



BOLO'GNIAN STONE, j phate of barytes, 

 possessing phosphoric properties. 

 These properties were first dis- 

 covered accidentally by Yicenzo 

 Casciarolo, an Italian shoemaker. 



BOEA'CIC ACID. A compound of 

 boron and oxygen, containing 

 about 26 per cent, of boron and 74 

 of oxygen. It is found native on 

 the edges of certain hot mineral 

 springs in Italy. It occurs in 

 scaly crusts, or small pearly scales, 



and massive. Homberg was the 

 discoverer of boracic acid. Boracic 

 acid may be obtained by adding to 

 a solution of borax half its weight 

 of sulphuric acid. The term Sas- 

 solin has been applied to boracic 

 acid, from its presence in the hot 

 springs of Sasso. 



BO'EACITE. Borate of magnesia; a 

 combination of boracic acid with 

 magnesian earth. Boracite is found 

 imbedded in gypsum, in Hanover 

 and Holstein ; its colours are white 

 and greyish ; it is generally of a 

 cubic form, and possesses, when 

 heated, strong electrical properties. 

 Borate of magnesia may be arti- 

 ficially obtained. Before the blow- 

 pipe boracite froths, emits a green- 

 ish light, and is converted into a 

 yellowish enamel. 



BO'EATE. A combination of boracic 

 acid with any saturated base ; a 

 salt formed by the combination of 

 any base with the acid of borax. 

 Parties. 



BO'EAX. (borax, Lat. lor ax, Er. lor ace, 

 It.) Subborate or borate of soda ; 

 a salt of soda formed of the alkali 

 with boracic acid . It is prepared 

 artificially by purifying the natural 

 borate of soda, a mineral found in 

 Thibet, where it is held in solution 

 in the waters of a lake, which also 

 contains common salt. Borax in 

 its impure state is called tincal- 

 and is purified by calcination, solu- 

 tion, and crystallization, after its 

 importation. Borax is an import- 

 ant article in the arts, as a flux in 

 the reduction of many metals, 

 especially in assaying ; it is also 

 used in medicine. According to 

 Berzelius, borax consists of soda 

 16-31, boracic acid 36-59, water 

 47-1. Bergmann states the pro- 

 portions to be boracic acid 34, soda 

 17, water 49; and Kir wan gives 

 as his analysis, boracic acid 84, 

 soda 17, water 47. 



BOBE. A violent rush of tidal water. 



