BIX

445

BL A

Bithynia . It was bounded on the \V. by the Bosphorus Thraciusand part of the Propontis , on the S. by the river Rhynuacu- andmount Olympus, on the N. by the Euxine sea , and on the Is. ou-tlie river Parthenius . The chief cities were Myrlea, Nicomedia,Chalcedon , Ileraclea, and Prusa.

B1TONTO, an episcopal town of Naples, in the Terra di Bari.Lon. 17. 40. E. Lat. 41. 20. N.

BITTER, Principal. Certain vegetables have an intenselybitter taste, which appears to be owing to the presence ofa peculiar substance, differing from every otherin its che-mical properties. It may be extracted trom quassia, gentian,the hop, and several other plants, by infusing them lot sometime in cold water. Dr. Thomson enumerates the charac-ters of this substance, as follows: 1. When water thus impreg-nated is evaporated to dryness by a very gentle heat, it. leaves abrownish yellow 7 substance which retains a certain degree of trans-parency. For some time it continues ductile, but at last becomesbrittle. Its taste is intensely bitter. 2. When heated it softens,swells, and blackens; then burns away without flaming much, andleaves a small quantity of ashes. 3. It is very 7 soluble in water andin alcohol. 4. It does not affect blue vegetable colours. 5. It isnot precipitated by the watery solution of lime, barytes, or stron-tites: nor is it changed by alkalies, d. Tincture of galls, infusionof nut-galls, and gallic acid, produce no effect. 7. Of the me-tallic salts, nitrate of silver and acetate of lead are the only onesthat throw it down. The precipitate by acetite of lead is veryabundant; and that salt, therefore, affords the best test for disco-vering the bitter principle when no other substances are present,bv which also it is decomposed. From recent experiments ofMr. Hatchett, it appears that the bitter principle is formed,along with tan, by the action of nitric acid on indigo.

Bitter, a sea term, signifying any turn of the cable about thebits, so as that the cable may be let out by little and little. Andwhen a ship is stopped by a cable, she is said to be brought up bya bitter. Also that end of the cable which is wound about the bitsis called the bitter end of the cable.

Bitters, in medicine. See Materia Mepica.

Bitter Apple, in botany. See Colocynthis .

Bitter End, in sea language, that part of the cable, which iswound about the bits, when the ship is at anchor.

BIT TERN, in ornithology. See Ardea.

Bittern, in the salt-works, the brine remaining after the saltis concreted : this they ladle off, that the salt may be taken outof the pan, and afterwards put in again ; when, being fartherboiled, it yields more salt. See Salt.

BITUMEN, in oryctology, a genus of the class of inflammablefossils. See Mineralogy. r I be true bituminous substancesmay be distinguished by the following properties: they are eithersolid, or of the consistence of tar: their colour is usually brown orblack: they have a peculiar smell, or at least acquire it whenrubbed ; this smell is known by the name of the bituminousodour: they become electric by friction, though not insulated :they melt when heated, and burn with a strong smell, a brightflame, and much smoke: they are insoluble in water and alcohol,but dissolve most commonly in ether, and in the fixed and vola-tile oils: they do not dissolve in alkaline leys, nor form soap:acids have little action on them : the sulphuric scarcely any: thenitric, by long and repeated digestion, dissolves them, and con-verts them into a yellow substance, soluble both in water andalcohol, and similar to the product formed by the action of ni-trous acid on resins.

Bitumen Judaicum. See Asphaltum.

BIVALVE , [from binus and vulva, Lat.] having two valvesor shutters; a term used of those fish that have two shells, asoysters; and of those plants whose seed-pods open their whole,length, to discharge their seeds, as peas.

Bivai.vular, [from bivalve,'] having two valves.

BIVENTER, in anatomy, called also digastric, or two-bellied,a muscle of the lowerjav.-. See Anatomy.

BIUMBRES, the same with the Amphiscii.

Ill XA, the Roucou or Arnotto tree: A genus of the monogy-nia order, and polyandria class; natural order, Coluinniferfe.Corolla ten-petaled; calyx quinquedented ; capsule hispid, bi-valved. There is one species,

R. Orellana, a native shrub of the warm parts of America .It rises with an upright stem to the height of 8 or 10 feel, sending

VOL. i.— no. 28.

out many branches at the top forming.a regular head, garnishedwith heart-shaped leaves ending in a point, and having long foot-stalks.

Bl/ANTINE, from Byzantium , a great piece of gold valuedat fifteen pounds, which the king oilers upon high festival days.

BIZARRO, in the Italian music, a fanciful kind of composi-tion, sometimes fast, slow, soft, strong, Sec. according to the com-poser’s fancy.

BlZOCllI, orBISOCIIl, in church history, certain hereticalmonks, said to have assumed the religious habit contrary to the.canons, rejected the sacraments, and maintained other errors.

BLACK, the darkest ot colours, supposed to be owing to theabsence of light, as most of the rays which fail on black substancesare not reflected, but absorbed by them. There are many shade--or varieties of this colour. The native black substances are,black chalk, pitcoal, black sands, black vegetable juices, and cut-tle-fish ink. Those which are the product of fire, comprehendcharcoal blacks, soot blacks, and black metallic calces. Blacksobtained by mixture, are those from iron, silver, and from a com-bination of lead with sulphur. The infusions of certain vegetableastringents, mixed with green vitriol (which is a solution of iron iathe sulphuric acid,) produce a deep black colour, of most exten-sive use for dyeing and staining. 'The astringent substances chief! veinployed for this purpose, are the excrescences of the oak-tree,called galls ; all parts of this tree, as the leaves, acorns, and moreparticularly the bark and wood. A great variety of other vegetablesubstances, such as the small branches and flowers of (he sumach-tree, alder bark, bistort root, and, in general, those which areastringent or corrugating to the taste, possess similar properties.The power by winch these vegetables strike black with vitriol,and their astringeney, are proportional to one another, and seemto depend on one and the same principle. Of the other proper-ties of {this astringent and colouring matter, little more is known,than that it is dissolved and extracted both by water and spirit ofwine, and that it does not exhale on the evaporation of the men-struum. Concerning black colours in general, we have the fol-lowing remarks by Dr. Lewis, in his Philosophical Commerce ofthe Arts : “ Of black, as’ of other colours, there are many shadesor varieties ; different bodies, truly and simply black, or whichhave no sensible admixture of any of the rest of the colours, asblack velvet, fine {black cloth, the feathers of the raven, Sec. ap-pearing, when placed together, of teints very sensibly different.2. One and the same body also assumes different degrees ofblackness, according to the disposition of the sensible part of itssurface; and in this respect, there is not, perhaps, any other co-lour which is so much affected by an apparent mechanism. Thusblack velvet, when the pile is raised, appears intensely black,much more so than the silk it was made from ; but on pressing thepile smooth, it looks pale, and in certain positions shews some-what even of a whitish cast. 3. This observation is agreeable tothe physical theory, which ascribes the blackness of bodies to theluminous rays that fall upon them, being in great part absorbed orstifled in their pores. When the surface is composed of a multi-tude ofloose filaments, or small points, with the extremities turnedtowards the eye, much of the light is stifled in the interstices be-tween them, and the body appears dark: when the filamentsare pressed close, or the surface smoothed and polished, more ofthe light is reflected from it, and the intensity of the blackness isdiminished ; though the beauty may be improved by the glossi-ness which results from the smoothing. 4. There is one case,however, in which a high polish may, on the same principle, pro-duce blackness, in bodies otherwise even while. e find thatspecula of white metal, or of quicksilvered glass, which reflect therays of light to one point or in one direction, look always dark,unless when the eye is directly opposed to the reflected rays. 5.As the absorption of the luminous rays, except in the case justmentioned, makes the physical cause of blackness; it is concludedthat black bodies receive beat more freely than others. Blackmarble or tiles, exposed to the sun, become sensibly hotter than,white ones. Black paper is kindled by a burning glass muchsooner than white, and the difference is strongly marked : a burn-ing glass, too weak to have any visible effect at all upon whitepaper, will readily kindle the. same paper rubbed over with ink.lienee black clothes when wetted are said to dry faster; blackhabits, and rooms hung with black, to be waimer’;. black mould,to be hotter soil for vegetables ; and garden walls, painted black,

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