B O L 



[ 33 ] 



BRA 



BOLE. (from/3w\o, Gr.) A friable clay, 

 or earth, often highly coloured with 

 iron. 



BOLE'TUS. A genus of mushrooms, of the 

 order Fungi. 



BOLO'GNA STONE. ) A variety of sulphate 



BOLO'GNIAN STONE. 3 of barytes, pos- 

 sessing phosphoric properties. These 

 properties were first discovered accident- 

 ally by Vicenzo Casciarolo, an Italian 

 shoemaker. 



BORA'CIC. Pertaining to borax ; containing 

 borax. 



BORA'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 

 ^rusts, or small pearly scales, and mas- 

 sive. Homberg was the discoverer of 

 boracic acid. Boracic acid may be ob- 

 tained by adding to a solution of borax 

 half its weight of sulphuric acid. The 

 term Sassolin has been applied to boracic 

 acid from its presence in the hot springs 

 of Sasso. 



BO'RACITE. Borate of magnesia ; a com- 

 bination of boracic acid with magnesian 

 earth. Boracite is found imbedded in 

 gypsum, in Hanover and Holstein ; its 

 colours are white and greyish ; it is gene- 

 rally of a cubic form, and possesses, when 

 heated, strong electrical properties. Bo- 

 rate of magnesia may be artificially ob- 

 tained. Before the blow-pipe boracite 

 froths, emits a greenish light, and is con- 

 verted into a yellowish enamel. 



Bo' RATE. A combination of boracic acid 

 with any saturated base ; a salt formed 

 by the combination of any base with the 

 acid of borax. Parkes. 



BO'RAX. (borax, Lat. borax, Fr. borace, 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 com- 

 mon salt. Borax in its impure state is 

 called tincal, and is purified by calci- 

 nation, solution, and crystallization after 

 its importation. Borax is an important 

 article in the arts, as a flux in the reduc- 

 tion of many metals, especially in assay- 

 ing ; it is also used in medicine. Accord- 

 ing to Berzelius, borax consists of soda 

 16-31, boracic acid 36'59, water 47'10. 

 Bergman states the proportions to be 

 boracic acid 34, soda 17, water 49 ; and 

 Kirwan gives, as his analysis, boracic 

 acid 34, soda 17, water 47. 

 BORE. A violent rush of tidal water. 

 BO'RON. The undecomposable base of bo- 

 racic acid ; this may be obtained by 

 heating in a copper tube two parts of 



potassium with one of boracic acid pre- 

 viously powdered and fused. 



Boss, (bosse, Fr.) A protuberance or 

 swelling ; a kind of knob or stud. 



BOSSED. Knobbed or studded. 



BOTHRODE'NDRON. (from fioOpoQ and 

 dzvdpov, Gr.) An extinct genus of coni- 

 feree belonging to the coal formation. 

 The bothrodendron has a stem not fur- 

 rowed, covered with dots. Scars of cones, 

 obliquely oval. The stems are marked 

 with deep oval or circular concavities, 

 which appear to have been made up by 

 the bases of large cones. These cavities 

 are ranged in two vertical rows, on 

 opposite sides of the trunk, and in some 

 species are nearly five inches in diameter. 

 Prof. Buckland. 



BO'TRYOID. ) (from /3orpv, a bunch of 



BOTRYOI'DAL. $ grapes, and Htioc, form.) 

 Resembling a bunch of grapes ; clustered 

 like grapes. 



BOTRY'OLITE. (from ftorpvg, a cluster of 

 grapes, and Xi'0oe, Gr.) Grape-stone ; 

 a variety of prismatic datolite, occurring 

 in mamillary concretions. 



BO'VEY-COAL, A name given to wood-coal 

 from its having been found in abundance 

 at Bovey Heathfield near Exeter ; called 

 also brown -coal. In wood-coal we may 

 almost seize nature in the act of making 

 coal, before the process is completed. 

 These formations of coal are far more 

 recent than those of common coal, and 

 have been referred to the first, or Eocene 

 period of the tertiary formations. Heat 

 and pressure appear to be required to 

 convert wood-coal into mineral coal. 

 Bovey-coal contains carbon 77'10, oxy- 

 gen 19'35, hydrogen 2-54, earthy parts 

 1-00. 



BOU'LDER. ^ Large fragments, or rounded 



BO'WLDER. { masses of any rock found 

 lying on the surface, or, sometimes, im- 

 bedded in soil, and differing from the 

 rocks where they are found ; these frag- 

 ments or outlying boulders, are of no 

 determinate size, they are supposed to 

 have been transported by the force of 

 water, and are occasionally found at very 

 great distances from their parent rocks. 

 The mass of rock on which is placed the 

 statue of Peter the Great at St. Peters- 

 burgh, is a detached block of granite, or 

 a boulder, forty-two feet in length, twen- 

 ty-seven feet broad, and twenty-one feet 

 high, and was removed from the Gulf of 

 Finland. 



BRACHELY'TRA. A family of coleopterous 

 insects, having but one palpus to the 

 maxillae. It comprises only one genus, 

 namely Staphylinus. 



BRA'CTEA. (bractea, Lat.) In botany, a 

 leafy appendage to the flower or stalk, 

 differing from the other leaves of the 



