BROUSSONETIA PAPYRIFERA 543 



removed to permit the entrance of air, the stopcock is opened, and the aqueous fluid is 

 permitted to run out. As soon as the highly-coloured ethereal solution arrives at the 

 aperture in the stopcock, the latter is shut ; a quantity of solution of potash is then 

 poured, by the upper aperture, into the globe, and the stopper is replaced. The whole 

 is now to be agitated, by which means the bromine combines with the potash, forming 

 a mixture of bromate of potash and bromide of potassium. The stopcock is again 

 opened, and the aqueous fluid received into an evaporating vessel, boiled to dryness, 

 and ignited. By this means the bromato of potash is all converted into bromide of 

 potassium. The bromine may bo procured from the bromide of potassium by distil- 

 lation with peroxide of manganese and sulphuric acid. In this operation one equiva- 

 lent of bromide, two equivalents of sulphuric acid, and one of peroxide of manganese, 

 yield one equivalent of sulphate of manganese, one of sulphate of potash, and one of 

 bromine; or, in symbols, KBr + 2S0 3 + Mn0 2 =KO,S0 3 + MnO,S0 3 + Br. (2KBr + 

 2SO i iwno X-SO' + IVInSO' + Br 2 ). The reaction, in fact, takes place in two 

 stages, but the ultimate result is as represented in the equation. 



Preparation 2. In some saline springs where bromine is present, accompanied by 

 considerable quantities of salts of lime, &c., the brine maybe evaporated to one-fourth, 

 and, after repose, decanted or strained from the deposit. The mother-liquid is to 

 have sulphuric acid added in order to precipitate most of the lime. The filtered fluid 

 is then evaporated to dryness, redissolved in water, and filtered ; by this means more 

 sulphate of lime is got rid of. The fluid is then distilled with peroxide of manganese 

 and hydrochloric acid. 



Preparation 3. Bromine may be obtained by Leisler's method, patented in 1866, 

 from the mother-liquors left in the treatment of the salts called carnallite and kainite, 

 found in the mines of Stassfurt in Prussia, and Kalucz in Hungary. When these 

 liquors are heated with bichromate of potash and dilute hydrochloric acid, the bromine 

 is distilled off, and may be condensed in a receiver containing pieces of iron whereby 

 a bromide of iron is formed. Stassfurt is now one of the chief localities for the 

 manufacture of bromine, and about 400 cwts. are produced there annually. 



Bromine, like chlorine, may be employed as a disinfectant. In medicine and in 

 photography it is used in the form of certain bromides, such as those of potassium, 

 ammonium, and cadmium. Bromine has also been employed in the preparation of 

 some of the aniline and anthracene colours. 



With hydrogen, bromine forms hydrobromic acid ; and with many of the metals it 

 forms well-defined bromides. A chloride of bromine is known, as also a bromide of 

 nitrogen the latter being an explosive compound resembling chloride of nitrogen. 

 The only well-developed oxide of bromine is bromic acid, Br0 4 HO (HBrO 8 ). 



Solutions of bromine in water may have their strength determined, even in presence 

 of hydrochloric or hydrobromic acids, by means of a solution of turpentine in alcohol. 

 One quarter of an equivalent of turpentine (34 parts) decolorises 80 parts or 1 equiva- 

 lent of bromine. 



BRO18TZXTE. A silicate of magnesia and protoxide of iron, with a metalloid 

 bronze-like lustre on the cleavage-planes. The species has been lately made to include 

 certain minerals formerly referred to the species Diallage such as the well-known 

 lustrous mineral in the Cornish serpentine. A green variety of bronzite occurs with 

 the diamonds of South Africa. 



BROOM, DYERS, or Greenweed. The Genista tinctoria, a dwarf shrub from 

 the flowers of which a bright yellow colour is obtained, which for dyeing green with 

 woad is said to be preferred by dyers to all other yellows. See WOAD. 



BROOMS. Sweeping brushes. These are made of cocoa-nut fibre, of date-palm 

 leaves, of broom-corn, and in this country of birch twigs, sedge, the common heath, 

 and of the broom. 



BROOM CORN. Sorghum dura. Cultivated in America to make brooms, the 

 grains being used as food for poultry. A closely allied grass, the Holcus saccharatus, 

 a native of China, abounds in sugar. This grass is generally known by the name 

 of Sorgho. It has been used from time immemorial by the inhabitants of China, 

 who extract sugar from it. The Toulon Agricultural Association recommended its 

 introduction into France, to take the place of beet-root. They state that it is richer 

 in sugar than any known plant, except the vine. Beet-root contains from 8 to 10 

 por cent, of sugar ; the sorgho from 16 to 20 per cent., from which about 8 per cent., 

 of pure alcohol can be obtained. The refuse is said to be excellent food for cattle. 

 The plant grows rapidly, and does not require irrigation. 



BRORA COAX. An inferior coal lying in the Oolitic deposits of Brora, in 

 Sutherland, Scotland. See COAI,. 



BROUSSOWETIA. PAPVRXFERA. The Paper Mulberry. The fibrous bark 

 is used in China and Japan for the manufacture of a kind of paper, while the Poly- 

 nesian islanders use it in the preparation of their Tapa cloth. 



