BRA 



BRA 



bronze, bell-metal, &c. most of which are 

 triple compounds, and will be noticed 

 under the article COPPER. 



BRASSICA, in botany, a genus of the 

 Tetradynamia Siliquosa class and order. 

 Natural order of Siliquosa Cruciformes. 

 Crucifer*, Jussieu. Essential character : 

 calyx erect, converging 1 ; seeds globular ; 

 a gland between the shorter stamens and 

 the pistil, and between the longer and 

 the calyx. There are sixteen species, 

 among which are the various kinds of 

 cabbages, bore-coles, brocolis, and tur- 

 nips. To give a short account only of 

 this important genus would exceed the 

 limits of our work; we can therefore re- 

 fer the reader with pleasure to Dr. Rees's 

 New Cyclopedia, where he will find, un- 

 der the words BRASSICA and CABBAGE, 

 every information he can desire, and al- 

 most every thing that can be interesting 

 on these subjects to the botanist, the gar- 

 dener, and the farmer. 



BRATHYS, in botany, a genus of the 

 Polyandria Pentagynia class and order. 

 Natural order, Rotaceae. Hyperica, Jus- 

 sieu. Essential character: calyx five- 

 leaved; petals five; nectary none ; cap- 

 sule one-celled, many-seeded. There is 

 but one species, viz. B Juniperina, a shrub 

 between heath and juniper, very branch- 

 ing and upright, the branches covered 

 with leaves; leaves opposite, very much 

 crowded, acerose, an inch long, acute, 

 unarmed, evergreen; flowers terminating 

 the branches, several together, sessile. 

 It is found in New Granada. 



BRAUNSPATH, pearl-spar, in mine- 

 ralogy, is milk-white, though passing by 

 different shades to the brownish red ; it 

 occurs generally crystallized, and the 

 forms of its crystals are the same as cer- 

 tain varieties of calcareous" spar. Its pri- 

 mative figure is a rhomboid, exactly cor- 

 responding with that of calcareous spar. 

 It is found of other figures, which are 

 described particularly by Hauy. The 

 external lustre is more or less shining 

 with a pearly lustre ; but, when in the 

 first state of decomposition, it has usually 

 a variegated semi-metallic appearance ; 

 it is a little harder than calcareous spar : 

 the specific gravity, according to Brisson, 

 is 2.83 ; but the Isabella yellow variety has 

 been found to be only 2.4. Before the blow- 

 pipe it crackles and falls to pieces, and 

 becomes of a brownish black colour, but 

 does not melt ; with borax it runs into a 

 frothy flag; it effervesces with acids when 

 pulverized. The massive variety, when 

 calcined and mixed with sand, forms a 

 strong and valuable cement, which sets 



quickly, and is impenetrable to water 

 The constituent parts are, 



Carbonate of lime .... 50 



Oxide of iron 20 



Oxide of manganese ... 28 

 100 



It occurs chiefly in veins, accompanied 

 by calcareous spar,galenablende. pyrites, 

 and various ores of silver. It is found in 

 the mines of Norway, Germany, Sweden, 

 France, and in some parts of England and 

 Wales. 



BRAWN, the flesh of a boar soused or 

 pickled ; for which end the boar should 

 be old ; because the older he is, the more 

 horny will the brawn be. 



BRAZIL -wood, in the arts. The tree 

 which bears this wood is the caesalpina 

 crista. The wood is very hard, takes a 

 high polish, and is so heavy as to sink in 

 water. When chewed it gives a sweetish 

 taste. It much resembles in appearance 

 red saunders wood, but differs from it es- 

 sentially in readily giving out its colour 

 to water, which saunders wood does not. 



Brazil wood is valuable for the beautiful 

 orange and red colours, in various shades, 

 which it furnishes to the dyer, but the 

 colour is naturally very fugitive, though 

 it may be to a certain degree fixed by va- 

 rious mordants. When raspings of Bra- 

 zil wood are boiled for some time in wa- 

 ter, they give a fine red decoction. The 

 residue appears black, but alkalies will 

 continue to extract a colour from it after 

 the action of water is exhausted. Spirit 

 of wine and ammonia also extract a co- 

 lour with great facility, which is some- 

 what deeper than the watery decoction. 

 A decoction of Brazil wood is readily 

 turned of a violet or purple blue by alka- 

 lies, and this change is produced by so 

 very minute a quantity, as to furnish a 

 chemical test of the presence of alkalies 

 of very great utility. According to Berg- 

 mann, 10 grains of crystallized carbonate 

 of soda, which contains no more than 

 about 2.15 grains of mere alkali, dissolv- 

 ed in something more than 5.5 English 

 pints of water, give a sensible purple 

 tingejto paper reddened by Brazil Wood. 

 There is, however, some ambiguity in 

 this test, as the same change is produced 

 by a solution of lime or magnesia in car- 

 bonic acid and water, a very frequent oc- 

 currence in most natural waters. Evapo- 

 rating the water for some time will dis- 

 tinguish whether the change on brazil 

 wood is produced by an alkali, or a car- 

 bonated earth : for, if by the former, the 



