5S1 



BORON. 



BOSWELLIA. 



BOROX. Minerals containing Boron or any of its compounds aa 

 an essential component part ai-e comparatively few in number, and 

 only found in a few spots ; it may be therefore considered as one of 

 the least predominating of the elements. It is the basis of Sassoline, 

 or native boracic acid ; Borax, or borate of soda ; Soracite, or borate 

 of magnesia ; Datholite, or borate and silicate of lime ; and Botryolite. 



It also enters as boracic acid into the composition of Axinite and 

 Tourmaline, but only in small quantity, most analyses giving between 

 two and three per cent, of the acid in the former mineral, and between 

 four and five per cent, iu the latter. 



The presence of Boron in any mineral may be readily detected with 

 the blow-pipe, owing to the beautiful green tint communicated to the 

 flame by the boracic acid. The facility with which the tint is 

 obtained depends on the element with which the boracic acid is 

 combined ; in every instance however it may be detected by the 

 following process : Iiet a flux, composed of 4 4 parts of bisulphate of 

 potash and one of finely-powdered fluor-spar, be well mixed with 

 about an equal quantity of the assay, which must then be formed 

 into a paste by the addition of a little moisture. A small quantity of 

 this being taken up on the extremity of a platinum wire must first be 

 dried, and then exposed to a high temperature until it ia fused, being 

 held within but near the extremity of the blue flame. When the 

 mass is fused it appears for a few moments enveloped in a pure green 

 flame, which soon disappears, and cannot be again produced. The 

 theory of the changes is this : The fluorine of the flux being set free 

 by the excess of sulphuric acid unites with the boron of the assay, 

 forming the fluoboracic acid, which at the moment of its volatilisation 

 communicates the green tint to the flame. This process is, however, 

 only necessary for the detection of the boracic acid in axinite and 

 tourmaline, as the flame 'is permanently coloured by sassoliue, 

 boracite, datholite, and botryolite ; and the same effect is produced 

 by moistening the glass of boron with sulphuric acid and again 

 fuing it. 



The native boracic acid is found op a deposit in several of the 

 lagunea of Tuscany, and also in considerable abundance in the hot 

 springs near Sasso in the same country, whence it has been called 

 Sauoline. It occurs in the form of thin scaly particles, or crystalline 

 grains either loose or aggregated in the form of a crust. These 

 crystalline grains are hydrated boracic acid, the constitution of which 

 may be expressed by the formula 



Boron 1 ; Oxygen 6 ; Water 6, 



as given by Berzelius, 100 parts of sassoline being composed of boracic 

 acid 56-37, water 43'63 : their specific gravity is 1'48. The lustre is 

 pearly, and the colour is grayish or yellowish-white : they are slightly 

 translucent. 



It loses ita water of crystallisation and fuses at a very low tempera- 

 ture, forming a glassy globule, which is a non-conductor of electricity, 

 and becomes resinously electric on friction. It has also been found 

 more recently by Dr. Holland to be a deposit of the solfatara within 

 the crater of Volcano, one of the Lipari Isles, being an exhalation of 

 the fumaroles, around the edges of which it forms thin filaments or 

 cakes on the surface of the sulphur. 



Borar, or borate of soda, is principally employed in the arts as a 

 flux in several metallurgical processes, and is very advantageously 

 used in the process of soldering metals. To the chemist it is an 

 invaluable re-agent in experimenting with the blow-pipe. 



Borax is soluble in twelve times its weight of cold and twice its 

 weight of boiling water, from which it may 

 be readily obtained in very perfect crystals of 

 the oblique prismatic system. The more usual 

 form of these is represented in the accom- 

 panying figure, where the faces r are the 

 vertical prism, the angles of which are, accord- 

 ing to the measurements of Phillips, 86 30' 

 and 93 30', the acuter edge of which is 

 truncated by M, the obtuser by T, while P 

 is the inclined terminal plane, and makes 

 with M an angle of 106 30'; O are the faces of a hemi-octohedron. 



The following are the measurements given by Phillips 



r on r 86 30' 



Ponr ., 101 30' 



M on r 133 20' 



P on M 106 30' 



P on O 139 15' 



on O 122 34' 



It ia very common to find the edges between and r truncated. 

 The specific gravity varies from 1'5 to 17; the hardness from 2 to 

 2'5. When coloured it is of a light yellowish-green : the fracture is 

 conchoidal and of a resinous lustre. 



The chemical composition as given by Berzelius is 



Boracic Acid 36';>2 



Soda 16-37 



Water 47'11 



Soracite is in many respects one of the most interesting bodies of 

 the inorganic kingdom. It was first described by Lasius in 1787 

 under the name of cubic quartz, and was found in the gypsum rocks 

 near Luneburg in Brunswick, where it occurs in small crystals, which 

 aiv perfectly developed on every side and imbedded in the gypsum. 



The crystals usually present a combination of the cube, dodecahedron, 

 and the two hemi-octohedrous, in which combinations sometimes the 

 one sometimes the other form predominates. The locality was for 

 some time the only spot where boracite was found, until the crystals 

 were discovered in a gypsum rock called Segeberg in Holstein, at the 

 foot of which is situated a small village of the same name. The crystals 

 of the Soracite of this spot possess the same characters as those of 

 Luneburg, and add considerable interest to the very peculiar rock in 

 which they are found, which is itself a very remarkable object from 

 its abrupt elevation over the sandy plain of Holstein. It is described 

 in the ' Geognostischen Aufsiitzen ' of Steflens, who considers it to be 

 of the same formation as the gypsum of the Paris basin. 



Boracite has been analysed by Stromeyer, who found it to be com- 

 posed of boracic acid 67, magnesia 33. The specific gravity is 2'9 ; it 

 is transparent, but also frequently opaque ; the hardness is 65 to 7 ; it 

 is brittle, and has a conchoidal fracture. The lustre is vitreous, 

 inclining to adamantine. The colour is usually a yellowish or greenish 

 gray. 



It fuses easily before the blowpipe, at first with much foam, and 

 then forms a glass globule, which crystallises on cooling, so that the 

 surface is covered with fine acicular points. When just so much soda 

 is added as will form with it a clear glass, it will then crystallise as 

 perfectly as the phosphate of lead. 



BORRERA, a genus of plants belonging to the natural order of 

 Lichent, named by Acharius in honour of William Borrer, F.L.S., who 

 has very successfully cultivated Cryptogamic Botany, especially that 

 of Great Britain. One species B. furfuracea has the reputation of 

 being astringent and febrifuge. A genus of Cinchonaceous plants has 

 also been named after Mr. Borrer. [BORREBIA.] 



BORRERIA, a genus of plants named in honour of William Borrer, 

 F.L.S. It belongs to the natural order Cinckonacece, and has the 

 following characters : Calyx with an ovate tube, and a permanent 

 limb which is parted into 2-4 teeth ; corolla salver-shaped or funnel- 

 shaped, 4-lobed ; stamens 4, exserted or inclosed ; stigma bifid or 

 undivided ; capsule crowned by the limb of the calyx, 2-celled, 

 opening from the apex at the dissepiment when mature, but without 

 any dissepiment ; coccse or nuts 1-seeded, opening by a longitudinal 

 chink inside. The species, which are very numerous, are most of 

 them herbs or undershrubs, and are nearly all natives of tropical 

 America. 



B. ferrwrinea, has a herbaceous, hard, erect, branched stem ; 

 tetragonal hairy branches ; oblong, acute, obliquely 3-4-nerved leaves, 

 scabrous above and pale beneath, and scabrous on the nerves from 

 hairs; bristles of the stipules the length of the sheath; whorls of 

 flowers globose, terminal, and axillary ; capsule downy, crowned by 

 the four subulate teeth of the calyx. This plant is a native of Brazil, 

 in elevated pastures in the provinces of Minas Geraes and St. Paul. 

 The plant is called Poaya, and Poaya da Maya at Cape Frio. This is 

 one of the plants which yield a bastard ipecacuanha. The roots are 

 of a brown colour, and when taken produce sickness and vomiting. 



B. Poaya is glabrous, and has a herbaceous simple tetragonal 

 stem ; sessile oblong-elliptic acute leaves, obliquely 6-nerved on both 

 sides of the midrib ; the stipules cleft into many long bristles ; whorls 

 of flowers capitate, sessile, few, axillary, and a larger terminal one ; 

 lobes of calyx 4, lanceolate linear acute, longer than the ovarium ; 

 corolla smooth; anthers exserted. A native of Brazil in elevated 

 pastures. It has blue flowers. The roots are white, and produce 

 sickness when taken, and are consequently frequently substituted for 

 ipecacuanha. The leaves when chewed have a sweet taste at first, 

 and afterwards an acid one ; a decoction of them is sometimes 

 employed in the cure of colic. Upwards of 80 species of this genus 

 have been described, of which only the above two appear to be used 

 by man. They may be cultivated in this country in greenhouses. A 

 light soil suits them best, and cuttings of the shrubby pieces readily 

 strike root under a hand-glass in heat. The herbaceous species 

 require the same treatment as other tender annuals. 



(Don, Gardener's Dictionary.) 



BOS. [BoviD-E.] 



BO'STRICHUS (Latreille), a genus of Insects belonging to the 

 order Coleoptera, of the family Xylophagi. Generic characters : 

 Body oblong, cylindrical, or nearly so; head rounded, capable of 

 being retracted within the thorax as far as the eyes ; eyes distinctly 

 projecting ; antenna; ten-jointed, short, the three terminal joints large 

 and distinct, twice as broad as the remainder ; the five following joints 

 small and close together ; the two remaining, or two basal joints, 

 slightly thickened ; palpi tolerably distinct, about equal in length to 

 the mandibles, short, and three-jointed ; thorax convex above, the 

 anterior part humped ; legs rather short, tarsi four-jointed, simple. 

 The insects of this tribe are found on old trees, upon which their 

 larvae feed, and in so doing they generally construct their burrows 

 under the bark. 



Boitrickm capucinu* (a rara species in this country) is about half an 

 inch long ; the head, antennae, thorax, and legs are black ; the rest of 

 the body is red. 



BOSWE'LLIA, a genus of balsamic plants belonging to the 

 natural order A myridacea. One of the species is believed by Cole- 

 to be the \iRnvos of Theophrastns, and th Thnrea itirga of 

 the Romans. (' Asiatic Researches,' vol. ix.) 



