Page:The American Cyclopædia (1879) Volume III.djvu/314

 308 BROMINE of the Mediterranean, 1-15 per cent. In the mineral springs of Kreuznach Ure found 10 - 8 grains; in Kissingen water, determined by Kastner, there is - 44 grain ; in Tenbury, Wor- cestershire, examined by Ure, as much as 12'5 j grains; and at Arnstadt, according to Har- tung, 13'6 grams. In the United States, bro- mine has been detected in various s-alinu springs, for the first time in the brines of Onondaga in 1830, by Hayes and Silliman. The quantity in one of the artesian wells of Saratoga, determined by Dr. Chandler, is 3'63 grains; in the brine of Saginaw valley Dr. Chilton found 7'65 grains ; at Tarentum, Penn., 6 grains ; in the Salina brine, analyzed by Dr. Goessmann, 1'36 grain per gallon is reported. Many mineral waters in all parts of the world have been shown to contain bromine, and for a long time the chief commercial supply was from these sources. Since the opening of the Stassfurt salt mines the chief product is derived from this source. As much as 300 grains per gallon has been obtained from the mother liquors of Stassfurt. Only two or three of the manufactories at this place have economized this substance, as the unprecedented supply has reduced the price below profitable manu- facture; the decrease in price has also been hastened by the large production in the United States. At Tarentum, Sligo, and Natrona in western Pennsylvania, at Pomeroy, Ohio, and at Kanawha, West Virginia, the manufacture of bromine has become of considerable impor- tance. The production in 1870 was 126,000 Ibs. In 1867 the production at Stassfurt WHS 20,000 Ibs. The cost in the United States in 1870 was $1 50 a pound. The preparation of bro- mine is conducted, according to Professor Miller, in the following manner : The mother liquor from the brine, after all the salts separable by crystallization have been removed, is subjected to a current of chlorine, care -being taken to avoid an excess of this gas, which would occa- sion inconvenience by forming a compound with the liberated bromine. All the bromides are readily decomposed by chlorine, the attrac- tions of chlorine being more powerful than those of bromine. In the foregoing operation chloride of magnesium is formed, and bromine is set free: MgBr 2 + Cl a =MgClj + Brj; the bromine shows itself by giving to the liquid a beautiful and characteristic yellow color. This yellow liquid, when agitated with ether, parts with its bromine, which is dissolved by the ether. If the mixture is allowed to stand in a glass globe closed at the bottom, the ether rises to the surface, where it forms a beautiful gold- en yellow layer. The mother liquor is drawn off by opening the stopcock, and the ethereal solution is agitated with a solution of hydrate of potash ; the yellow color immediately dis- appears; bromide and bromate of potassium are formed and dissolved in the water : 3Brc, + 6KHO = KBrOs, + 5KBr + 3H a O ; while the ether, after repose, rises again to the surface despoiled of its bromine, and may again be employed in a repetition of tlie process upon a fresh quantity of bittern. When the solution of potash has, by repeated charges of bromine, been nearly neutralized, the liquid is evapo- rated to dryness; the saline mass is gently ignited, to decompose the bromate ; after which it is mixed with peroxide of manganese, and distilled in a retort with sulphuric acid. Dense red vapors of bromine pass over, which may be collected in a receiver containing water, and kept cool by ice. The decomposition is of the same nature as that attending the liberation of chlorine from sea salt by means of oxide of manganese and sulphuric acid : 2KBr + MnO 2 this operation a small quantity of chlorine passes over with the bromine, since, from the manner in which the bromide of potassium is formed, it is always contaminated with a por- tion of chloride of potassium. The chlorine unites with part of the bromine, forming chlo- ride of bromine, which is partially decomposed and dissolved by the water in the receiver, while the bromine is condensed in red drops. In order to obtain bromine free from chlorine, it must be saturated with hydrate of baryta, which produces a mixture of bromide and chlo- ride with bromate of barium; this mixture must be heated to redness in order to convert the bromate into bromide of barium, and the residue digested in alcohol, which dissolves nothing but the bromide ; the bromide of ba- rium is obtained by evaporation of its alcoholic solution, and when heated with black oxide of manganese and sulphuric acid t it yields pure bromine. Bromine forms a red liquid, so deep in color as to be nearly opaque. It has a spe- cific gravity of 2'966 at 60 ; it is very volatile, and emits dense red vapors resembling peroxide of nitrogen in color. It resembles chlorine in smell, and is extremely irritating to the nose and- fauces when respired, even if largely di- luted with air. When swallowed it operates as a powerfully irritating poison ; it acts rap- idly on all the organic tissues, and renders the skin permanently yellow. Bromine boils at 145 - 4 F., and when exposed to a temperature 6f 9'5 it forms a red crystalline solid. The properties of bromine greatly resemble those of chlorine, though they are less strongly de- veloped. It bleaches many vegetable colors. Its vapor will not support the flame of a burn- ing taper. Bromine is slightly soluble in water, and gives to it a yellow color; it also forms with it a hydrate (Br5II 2 O) which crystallizes in octahedra at 32 F. This aqueous solution of bromine is decomposed by sunlight into hy- drobromic acid and oxygen. Alcohol dissolves bromine freely, and ether does so still more abundantly. Olefiant gas is rapidly absorbed by liquid bromine, and a. liquid compound (OiHiBrt), bichromide of ethylene, is formed. Bromine combines directly with phosphorus, and with many of the metals, forming com- pounds termed bromides, the act of combi- nation being often attended with ignition, as