BROMUM - BROMINE, Br,=80.

This element is contained in sea-water and in some saline springs, as in those of Ashby, Birtley (Durham), Woodhall, and Kreuznach, also in sea-weed and in molluscs.

Preparation

Bromine is chiefly obtained after the crystallization of common salt, from "bittern" or sea-water (in which it exists as bromide of magnesium, sodium, and potassium), by passing through the liquid, chlorine gas, which sets free the bromine. The mixture is then shaken up with ether, which dissolves the bromine and rises to the surface and is decanted. To this ethereal solution caustic potash (or soda) is added, and the ether evaporated off by heat. The crystals of bromide of potassium thus obtained are treated with sulphuric acid and manganese oxide, and the liberated bromine is evaporated and collected in cooled receivers.

The reactions are: - (1) MgBr2 + 2Cl=MGCl2+2Br. (2) 6Br+6KHO =5KBr+KBrO3+3H1O. (3) 2KBr+3H1SO4 + MnO2=2KHSO4 + Mn S04 + 2H10 + Br2.

The potassae bromas (KBrO3) formed in the second reaction is converted into potassium bromide (KBr) by ignition before the final process.

Characters And Tests

Bromine is the only non-metallic element which is liquid. It is of brownish red color, very volatile, and emits an irritating, very fetid vapor, whence its name, Bpouos, a stench. It boils at 145.4° F. (Pierre) (139.1° F., Bolas and Grove), not 117°, as stated in the British Pharmacopoeia. Iodine, chlorine, and alkalies decolorize bromine, with formation of bromides and bromates, and in contact with hydrogen-compounds it forms bromhydric acid. Solutions in alcohol and ether (which liquids dissolve bromine readily) lose their color in a few days with formation of the same acid. Bromine should be kept in a stoppered bottle, and under water, in which it is only slightly soluble. At 32° F. it forms with water a crystalline hydrate.

Physiological Action

Bromine coagulates albumen and combines with it in a definite proportion of Br. 23, albumen 96, which compound is soluble in caustic potash, and is colorless (Glover: "Harveian Essay," 1842).

Undiluted bromine quickly oxidizes and destroys organic tissues, forming a brownish slough. With fatty substances hydrobromic acid is developed. Bromine vapor is intensely irritating to the air-passages, possibly on account of its liberating free ozone on contact with moist mucous surfaces exposed to air. It may cause coryza, or even laryngitis, bronchitis, or pneumonia, and may destroy the sense of smell.

When taken internally in doses of one to two drops, well diluted, it has a taste "truly horrid" (Glover), and causes weight and heat at the stomach, often colic, shooting pains in the limbs, and itching in the extremities; but after an hour or so these symptoms are succeeded by a general sense of comfort and stimulation. Larger doses may cause gastritis with symptoms of intense irritation, prostration, and collapse. Independently of this local irritant effect, the physiological action of bromine, after absorption, is exerted mainly on the lymphatic and glandular systems, their functional activity being increased.

Kohler mentions several experiments which have been made with bromine, and says, "that, independent of its local action, it exerts, if taken in small doses for some time, a strong action upon the brain, viz., depression of the mental functions, sleepiness, stupor, prostration, and a state resembling alcoholic intoxication." On the other hand, bromine does not show the peculiar depressing action of its potash salts on the heart, nor their special effect on the spine of lowering its reflex irritability.

Therapeutical Action (External)