4GO BOUGIE 



BOROC AIiCXTE. A borato of lime. Seo BOKACIC ACID, 



BORON. Ono of the non-metallic elements ; it exists in nature in the form of 

 boracic acid, and as borax, tincal, boracito, borocalcite, &c. 



Hombcrg is said to have obtained boron from borax in 1702; if so, his discovery 

 appears to have been forgotten, since it -was unknown, except hypothetically, to the 

 more modern chemists until, in 1808, it was obtained by Gay-Lussac and Thenard, 

 and by Davy in 1808, who decomposed boracic acid into boron and oxygen. 



Boron is best obtained from the double fluoride of boron and potassium (BF 3 .KF), 

 which is prepared by saturating hydrofluoric acid with boracic acid, and then gradually 

 adding fluoride of potassium. The difficultly soluble double compound thus produced 

 is collected and dried at a temperature nearly apprbaching to redness. This compound 

 is then powdered and introduced into an iron tube closed at one end, together with 

 an equal weight of potassium, whereupon heat is applied sufficient to melt the latter, 

 and the mixture of the two substances is effected by stirring with an iron wire. Upon 

 the mass being exposed to a red heat, the potassium abstracts the fluorine. The 

 fluoride of potassium may afterwards be removed by heating the mass with a solution 

 of chloride of ammonium, which converts the free potassa into chloride of potassium, 

 and thus prevents the oxidation of the boron, which takes place in the presence of 

 potash ; the chloride of ammonium adhering to the boron may be afterwards 

 removed by treatment with alcohol. Boron thus prepared is a dark greenish-brown 

 powder, tasteless, and inodorous ; its atomic weight is ll'O. 



MM. "Wohler and Deville have, by fusing boracic acid, or amorphous boron, with 

 aluminium, succeeded in obtaining boron in the crystallised state. The form of the 

 boron crystals thus obtained has been the subject of a remarkable enquiry by M. 

 Quintino Sella. They are octahedra, belonging to the pyramidal or square prismatic 

 system. They refract light powerfully, have a specific gravity of 2-68, and seem to 

 bo almost as hard as diamond. From the close resemblance of this form of boron to 

 the diamond, it is generally known as Adamantine or Diamond 'Boron. 



Accompanying this octahedral boron , as it crystallises from its solution in 

 aluminium, are certain copper-coloured six-sided scales, strongly resembling graphite, 

 and hence called graphitoidal boron. It has been lately shown, however, that this 

 substance, instead of being an allotropic form of boron, is really a definite compound 

 of boron and aluminium. Seo BORACIC ACID. 



BORONATROCAXiCXTE. A synonym of Ufexite. See BORACIC ACID. 

 BOS JEIVIAWTTE. A name given to Manganese Alum. See ALUM, NATIVE. 

 COTALI.ACK.ITE. An oxychloride of copper found at Botallack Mine, in St. 

 Just, Cornwall. 



BOTTXiE MANUFACTURE. See GLASS and STONE WARE. 

 BOUGIE. A smooth, flexible, elastic, slender cylinder, introduced into the 

 urethra, rectum, or oesophagus, for opening or dilating it, in cases of stricture and 

 other diseases. The invention of this instrument is claimed bv Aldereto, a Portuguese 

 physician ; but its form and uses were first described by his pupil Amatus, in the 

 year 1554. Some are solid and some hollow, some corrosive and some mollifying. 

 They owed their elasticity, as formerly made, to linseed oil, inspissated by long boiling, 

 and rendered dry by litharge. This viscid matter was spread upon a very fine 

 cord or tubular web of cotton, flax, or silk, which was rolled upon a slab, when it 

 became nearly solid by drying, and was finally polished. 



Pickol, a French professor of medicine, published the following recipe for the com- 

 position of bougies : Take 3 parts of boiled linseed oil, 1 part of amber, and 1 of oil 

 of turpentine; melt and mix these ingredients well together, and spread the com- 

 pound at 3 successive intervals upon a silk cord or web. Place the pieces so 

 coated in a stove heated to 150 F. ; leave them in it for 12 hours, adding 15 or 16 

 fresh layers in succession, till the instruments have acquired the proper size. Polish 

 them first with pumice-stone, and finally smooth with tripoli and oil. This process 

 is the one still employed in Paris, with some slight modifications ; the chief of which 

 is dissolving in the oil one-twentieth of its weight of caoutchouc, to render the sub- 

 stance more solid. For this purpose the caoutchouc must be cut into slender shreds, 

 and added gradually to the hot oil. The silk tissue must be fine and open, to admit 

 of the composition entering freely among its filaments. Every successive layer 

 ought to bo dried in a stove, and then in the open air, before another is applied. This 

 process takes 2 months for its completion, in forming the best bougies called by dis- 

 tinction elastic bouqics ; which ought to bear twisting round the finger without crack- 

 ing or scaling, and extension without giving way, but retracting when let go. When 

 the bougies are to bo hollow, a mandrel of iron wire, properly bent, with a ring at one 

 end, is introduced into the axis of the silk tissue. Some bougies are made with a 

 hollow axis of tinfoil rolled into a slender tube. Bougies are now usually made entirely 

 of caoutchouc, by the intervention of a solution of this substance in sulphuric ether, a 



