BRAZIL WOOD 473 



bustion is produced. By carefully washing the coal and drying it, these casualties 

 might be almost entirely prevented. BRASS is a name given to an iron ore found in 

 the coal-measures of South Wales, which is not a pyritic ore, although for a long 

 period mistaken for it. See COAL BRASS. 



BRASSIIi. A name given to iron pyrites in Derbyshire, ' a hard substance, and 

 fiery, but yields no metal.' Hodson, Complete Derbyshire Miner. 



BRASSING IRON. Iron ornaments are covered with copper or brass by pro- 

 perly preparing the surface, so as to remove all organic matter, which would prevent 

 adhesion, and then plunging them into melted brass. A thin coating is thus spread 

 over the iron, and it admits of being polished or burnished. The electro-magnetic 

 process is now employed for the purpose of precipitating brass on iron. This process 

 was first mentioned in Shaw's ' Metallurgy,' in 1844, where he remarks: 'In depo- 

 siting copper upon iron, a solution of the cyanide or acetate of copper should 

 bo employed. The only value of these salts is, that the surface of iron may bo 

 immersed in their solutions without receiving injury by the corrosion consequent upon 

 the deposition of a film of metal by chemical action.' The following solutions are 

 recommended by Dr. "Woods, in the 'Scientific American,' for coating iron with 

 copper, zinc, or brass, by the electrotype process : 



To make a Solution of Copper or Zinc. Dissolve 8 ounces (troy) cyanide of potas- 

 sium and 3 ounces of cyanide of copper or zinc in 1 gallon of rain or distilled water. 

 These solutions to be used at about 160 F. with a compound battery of from 3 to 12 

 cells. 



To prepare a Solution of Brass. Dissolve 1 Ib. (troy) cyanide of potassium, 2 

 ounces of cyanide of copper, and 1 ounce of cyanide of zinc, in one gallon of rain or 

 distilled water ; then add two ounces of muriate of ammonia. This solution is to bo 

 used at 160 F. for smooth work, and from 90 to 120, with a compound battery of 

 from 3 to 12 cells. See ELECTRO-METALLURGY. 



BRATTICE. The division made in a shaft of a colliery is so called. It is used 

 to ensure an up and a down-cast current of air. Brattices may be also used in any 

 of the levels for the same purpose. They may be of metal, of wood, or tarred canvas. 

 Mining engineers speak of a natural brattice, i.e. one independent of any artificial 

 arrangement when the currents separate naturally in a shaft or a level and thus 

 produce a natural ventilation. 



BRAUCTITfi. A scsquioxide of manganese, composed when pure of nearly 70 

 per cent, of manganese, and 30 per cent, of oxygon. 



BRAZILIAN ARROWROOT. See ARROWROOT. 



BRAZIXi WITTS. The hard-shelled fruit of the Bertholktia cxcelsa, which is 

 roundish and about six inches in diameter, contains about two dozen of the elongated 

 wrinkled triangular seeds these are the ' nuts ' of the shops. See PARA NUTS. 



BRAZX& WOOD. (Bois de Pernambouc, Fr. ; Brasilicnholz, Ger.) This dye- 

 wood gives its name to the part of America whence it was first imported. It has 

 also the names of Pernambuca, Wood of St. Martha, and of Sapan, according to the 

 places which produce it. Linnaeus distinguishes the tree which furnishes the Brazil 

 wood by the name of Cassalpinia crista. It commonly grows in dry places among 

 rocks. Its trunk is very large, crooked, and full of knots. It is very hard, suscep- 

 tible of a fine polish, and sinks in water. It is pale when newly cleft, but becomes 

 rod on exposure to the air. The following is a very exact description of the tree pro- 

 ducing this wood: 



The ibiripitanga, or Brazil wood, called, in Pernambuco, pao da rainha (Queen's 

 wood), on account of its being a Government monopoly, is now rarely to be seen within 

 many leagues of the coast, owing to the improvident manner in which it has been 

 cut down by the Government agents, without any regard being paid to the size of the 

 tree or its cultivation. It is not a lofty tree. At a short distance from the ground, 

 innumerable branches spring forth and extend in every direction in a straggling, 

 irregular, and unpleasing manner. The leaves are small and not luxuriant ; the wood 

 is very hard and heavy, takes a high polish, and sinks in water ; the only valuable 

 portion of it is the heart, as the outward coat of wood has not any peculiarity. The 

 name of this wood is derived from brasas, a glowing fire or coal ; its botanical name 

 is Cassalpinia Brasileto. The leaves are pinnated, the flower white and papilionaceous, 

 growing in a pyramidal spike : one species has flowers variegated with red. The 

 branches are slender and full of small prickles. There are nine species. See Bell's 

 ' Geography.' 



The species Brasileto, which is inferior to the crista, grows in great abundance in the 

 West Indies. The demand for the Brasileto, a few years ago, was so great, owing to its 

 being a little cheaper than the crista, that nearly the whole of the trees in the British 

 possessions were cut down and sent home, which Mr. Bell very justly terms improvi- 

 dence. It is not now so much used, and is consequently scarcer in the English market, 



