BOM 



BO R 



spar. 7. Blue blacJc is another name for 

 ivory black. 



BLUFFS. A term employed in the 

 United States to designate high banks 

 presenting a precipitous front to the sea 

 or a river. 



BODY. A term applied in Physics to 

 any determinate part of matter, but of 

 itself utterly passive, capable of any sort 

 of motion, and of all figures and forms. 

 Body, or substance, which is the same 

 thing, is usually denoted by the general 

 term matter. Its forms are the solid, as 

 crystals ; and the fluid, which are elastic 

 and aeriform, as gases, or inelastic and 

 liquid, as water. In Geometry, the term 

 body is synonymous with solid. 



BOG-EARTH. An earth composed 

 of light siliceous sand and about 25 per 

 cent, of vegetable fibre in a decomposing 

 state. 



BOG IRON ORE. A ferruginous de- 

 posit, occurring at the bottom of peat 

 mosses and in marshy places, owing to 

 the presence of oxide of iron in solution 

 in almost all water. These ferruginous 

 matters sometimes form, below the soil, 

 a plate, or pan, which is impermeable to 

 the roots of trees. 



BOILING POINT. That degree in 

 the scale of the thermometer, at which 

 ebullition is produced under the medium 

 pressure of the atmosphere. Thus, 212° 

 is the boiling point of water, when the 

 barometer stands at 30 inches ; at 31 

 inches, it is 213*76; at 29, it is only 210*19; 

 in a common vacuum, it is 70°. 



BOLE (/3te»\of, a mass). A friable 

 earthy substance, a species of the soap- 

 stone family. It is found in Lemnos, 

 and is hence termed Lemnian earth ; also 

 in Armenia, France, and other places. 

 Its colours are yellow-red, and brownish- 

 black, when it is called mountain soap. 



BOLE'TIC ACID. An acid procured 

 from the expressed juice of the Boletus 

 pseudo-igniarius, a species of mush- 

 room. 



BOLO'GNIAN STONE. Native sul- 

 phate of barytes; a phosphoric stone 

 found at Bologna. When heated with 

 charcoal, it becomes a powerful solar 

 phosphorus. 



BOMBIC ACID (/36M/3i;f, the silk- 

 worm). An acid contained in a reservoir 

 near the apus of the silk-worm. It forms 

 salts with the alkalies, earths, and me- 

 tallic oxides, which have been called 

 hombiates. 

 BOMBY'CID^ {bombyx, the silk- 

 55 



worm). A tribe of Lepidopterous insects, 

 named from the genus Bombyx, and 

 consisting of Moths allied to the common 

 silk-worm. The principal characteristics 

 of the family are the presence of merely 

 rudimentary maxillae, remarkably small 

 palpi, and bipectinated antenna?. 



BOMB Y'LID^. A family of Dipterous 

 insects, named from the genus Bomby^ 

 lius, and distinguished chiefly by their 

 long proboscis. 



BONE EARTH. The residue of bones 

 which have been calcined, and converted 

 into a friable substance, consisting chiefly 

 of phosphate of lime. 



BOO'TES. A northern constellation, 

 containing fifty-four stars, the principal 

 of which is Arcturus. 



BORA'CIC ACID. An acid compound 

 of boron and oxygen, formerly called 

 Homberg's sedative salt and sedative salt 

 of borax. It occurs native on the edges 

 of hot springs in Florence, &c., in small 

 pearly scales, and also in a massive 

 state. It forms salts with bases, which 

 are called borates, of which the only im- 

 portant one is borax. 



BO'RACITE. A mineral consisting 

 of an anhydrous compound of magnesia 

 and boracic acid, in the extraordinary 

 ratio of 3 equivalents of the former to 4 

 of the latter. The rare mineral hydro- 

 boracite is said to be a compound of a 

 borate of lime and borate of magnesia, 

 in both of which the acid and the base 

 are in the same ratio as in boracite, with 

 18 equivalents of water. 



BORAGINA'CEiE. The Borage tribe 

 of Dicotyledonous plants. Herbaceous 

 plants or shrubs, with leaves alternate, 

 covered with asperities ; corolla gamo- 

 petalous; stamens inserted in the corolla; 

 fruit, four nuts, distinct. 



BORAX {baurach, Arab.)- A native 

 bi-borate of soda, chiefly found in an im- 

 pure state, and then called tinkal, or 

 rough borax, as a saline incrustation in 

 the beds of certain small lakes in an up- 

 per province of Thibet. When the re- 

 fined salt is deprived of its water of 

 crystallization by fusion, it forms a vi- 

 treous transparent substance, called glass 

 of borax. 



BOREAL SIGNS. Those on the north 

 side of the equinoctial ; viz. Aries, Tau- 

 rus, Gemini, Cancer, Leo, and Virgo. 



BORNEEN. The name given to a 

 compound of carbon and hydrogen found 

 in valeric acid, supposed to be identical 

 with liquid camphor. 



D4 



