Page:Encyclopædia Britannica, Ninth Edition, v. 4.djvu/409

Rh Destroyed in war it was restored by Casimir of Poland in 1346, and down to the close of the IGth century it con tinued to be a flourishing commercial city. It afterwards suffered so much from war and pestilence that about 1772, when the Prussians took possession, it contained only from five to six hundred inhabitants. By the treaty of Tilsit it was transferred to the duchy of Warsaw; in 1813 it was occupied by the Russians, and in 1815 it was restored to Prussia. Population in 1871, 27,740.  BROME,, a minor English poet, was born in 1620, and died in 16GG. He was an attorney in the lord mayor s court, and was the author of many of the songs and epigrams that were published in favour of the Royalists and against the Rump. These, together with his epistles and epigrams, translated from different authors, were all printed in one volume, octavo, after the Restoration. He published a translation of Horace by himself and others, and was the author of a comedy entitled The Cunning Lovers. He also edited two volumes of Richard Brome's plays.  BROME,, a dramatic writer in the reign of Charles I., and a contemporary of Dekker, Ford, Shirley, and others. He was originally a servant of Ben Jonson ; but he soon acquired a high literary reputation, and was addressed in some lines by his quondam master on account of his comedy entitled Tke Northern Lass. Brome s genius lay entirely in comedy. His plots are original and well managed, and his characters, which for the most part are strongly marked, were drawn from his own experience. He has left fifteen comedies. See Ward s English Dramatic Literature, 1875, vol. ii., for a good notice of Brome.  BROMINE, one of the halogen group of non-matallic chemioiil elements, which comprises three other members, chlorine, iodine, and fluorine. The whole group has many properties in common, the most marked being their be haviour towards hydrogen, uniting with it atom for atom, forming, gaseous condensible acid compounds, which are all produced by similar reactions, and which yield in combina tion with metals crystals of uniform structure. Bromine was discovered in 1826 by Balard, who extracted it from the water of the Mediterranean during his researches in connection with the sea-water. At ordinary temperatures it is a deep brownish-red liquid, emitting a strong disagree able odour (whence its name, from /3pw/xos, a stink), having a specific gravity of 2 - 9G, freezing into a red-brown crystalline mass at - 24 - 5 C., and boiling at 63 C. Its combining equivalent or atomic weight is 80. Bromine is an element of great chemical activity, and of the highest interest in scientific chemistry on account of its combinations, and especially on account of the products of its substitution for hydrogen in organic compounds. Although very widely disseminated, since it is found in ocean water, bromine is nowhere an abundant element. It i-s a constituent of some silver ores from Mexico and South America ; it is very generally found in strong saline springs, as well as associated with deposits of salt ; and it is present in many marine plants. The waters of the Atlantic, accord ing to Von Bibra, contain 24 grains per gallon ; while Here- path s analysis gives Dead Sea water a strength of 121 - 5 grains per gallon. It is only from the waters of certain saline springs in America that bromine is prepared as a direct product. At several places in western Pennsylvania and West Virginia the manufacture is carried on exten sively, 1 25,000 Ib having been extracted in 1870. In Europe bromine is only obtained as a secondary product of the preparation of potash and other alkaline salts, its chief source being the mother-liquors of the kelp manufacture, brine springs, and especially the Stassfurth saline deposits, near Magdeburg, Prussia. The produce at Stassfurth in 1873 amounted to about 10,000 Ib ; and it is estimated that the yield of English and French works was, taken together, about the same. On the commercial scale bromine is prepared at Stassfurth from the liquids which have been exhausted of all their crystallizable soda and potash salts, and from which also a deposit of chloride of magnesium has been obtained. This final mother-liquor is found to contain from 3 to 5 per cent, of bromine, in the form of bromide of potassium. To separate the bromine the liquor is introduced into a sand stone apparatus similar to that used for the evolution of chlorine from common salt, the process and reaction being similar in both cases. In this it is mixed with black oxide of manganese and sulphuric acid in definite proportions, and heated by a current of steam. The red vapour of bromine is given off and led by a pipe into a condensing worm of earthenware, and received into a series of three Woulfe s bottles, the first of which contains water, and the others alkaline ley and iron filings. The reaction which takes place is thus represented—

= 2KHS0 4 + MnS0 4 ~+ 2H 2 &quot;0 + 2Br , —sulphates of potash and manganese, water, and free bromine being produced from bromide of potassium, man ganese dioxide, and sulphuric acid. Pure bromine vapour distils over at first, but as the distillation proceeds chlorine is gradually evolved, and from this the bromine may be freed by shaking up with a solution of bromide of potassium, which yields up its bromine to combine with chlorine. On account of its peculiarly irritating action on the organs of respiration, very great precautions have to be taken to pro tect workmen from the fumes of bromine, and it is indis pensable that those engaged in the industry should abstain from all alcoholic liquors. The chief industrial application of bromine and its com pounds is in medicine, for which it is used in the form of bromide of potassium, bromide of ammonium, and bromide of sodium, besides in various combinations with alkaloids and organic substances. It is, however, most largely employed as bromide of potassium, a salt prepared on the large scale by the decomposition of potassium carbonate by the bromide of iron. It is also prepared by passing the vapour of bromine into a solution of caustic potash, when a mixture of bromide and bromate of potassium is produced. The mixed salts are reduced to a uniform bromide by burning with coal dust. Bromide of silver is employed to some extent in photography, and, according to the experi ments of Vogel, it possesses a peculiar sensitiveness for the red, green, and yellow colours, which are not acted on by other photographic agents. During the American Civil War (1861-5) bromine came into use as a disinfectant in military hospitals, a purpose to which it was also applied in the Franco-German War in 1870-1. For such purposes it was found to possess several advantages over chlorine, which, however, has the recommendation of cheapness and abundance. It has long been hoped that bromine might be substituted for iodine in the preparation of the several coal- tar colours, but hitherto the attempts in that direction have not been successful. Eosme, a tetrabromated potassium salt, is the only dye into which bromine at present enters. The use of bromine has been suggested by Dr Rudolf Wagner in several metallurgical operations, in which he anticipates it might be of great service. He proposes, in place of the pre sent wasteful method of reducing mercury from cinnabar, to digest the ere in an aqueous solution of bromine, whereby a bromide of mercury would be formed. He also suggests that bromine might be advantageously applied to the extraction of gold from poor auriferous ore, in a manner analogous to Plattner s chlorination process. Further, it is recom- 