2. As the last, but using fine wheat flour in lieu of sago-meal. Made into a beverage in a similar way to cocoa.
BRO′MAL. C2Br3HO. A colourless, oily liquid, obtained by the action of bromine on alcohol. Sp. gr. 3·34; boiling point above 212° F. Like chloral it yields a solid hydrate with water. Because of its powerful irritant properties it seems unlikely to prove useful, either as a hypnotic or as an anæsthetic.
BRO′MIDE (-mĭd). Syn. Bro′muret*, Hydrobro′mate*; Bromi′dum, Bromure′tum, Hydrobro′mas, L.; Bromide, Bromure. Fr. A chemical compound of bromine with another radical.
Prop., &c. The soluble bromides give white precipitates with nitrate of silver, acetate of lead, and protonitrate of mercury. That from the first of these is insoluble in dilute nitric acid and in ammonia water unless concentrated; and it has a slight yellowish tinge, changing to a violet on exposure to the light. A few drops of liquid chlorine poured upon a bromide, followed by agitation of the mixture with a little sulphuric ether, furnishes an ethereal solution of bromine. [For the other bromides see the respective bases.]
BRO′MINE (-mĭn), (bromos, a stink). Br. Syn. Brome*; Bro′mium, Bromin′ium, L.; Brôme, Fr. An elementary substance, discovered by M. Balard, of Montpellier, in 1826.
Prep. 1. A current of gaseous chlorine is passed through the uncrystallisable residuum of sea-water called bittern, which then assumes an orange tint, in consequence of bromine being set free from its combinations; sulphuric ether is then agitated with it, and the mixture is allowed to stand, in a close vessel, until the ethereal portion floats upon the surface. This is a solution of crude bromine, and for common purposes the ether may be at once evaporated by a very gentle heat. To render it pure, caustic potassa is added in excess to the ethereal solution, or the latter is agitated with a solution of potassa, by which means bromide and bromate of potassium are formed. The whole is evaporated to dryness, and submitted to a dull red heat. The residuum is next powdered and mixed with pure peroxide of manganese; the mixture having been placed in a retort, sulphuric acid (diluted with half its weight of water) is poured in. Red vapours immediately arise, and condense into drops of bromine, which are collected by plunging the neck of the retort nearly to the bottom of a small receiver
containing a little very cold water. The bromine forms a stratum beneath the water, and may be collected and at once put into a stoppered bottle; or it may be further purified by distillation from dry chloride of calcium.
2. Leisler’s patent for a method of obtaining bromine consists in decomposing the lye containing the bromine salt by heating it with hydrochloric acid and bichromate of potash in a leaden still having an earthenware head. The volatilised bromine with the vapour of water is conducted into a receiver containing iron turnings, bromide of iron, which dissolves in the water contained in the receiver, being formed. The bromide of iron so produced is either converted into other metallic bromides by the usual processes, or the bromine is obtained in a separate state from the iodide by treatment with sulphuric acid and bichromate of potash.
3. Large quantities of bromine are extracted from the mother liquor of carnallite, a double chloride of magnesium of potassium occurring in enormous quantities in a bed of clay in the neighbourhood of Stassfurt, near Magdeburg. The mother liquid of the carnallite at 35° B. is first freed as much as possible from the chloride of calcium it contains, by means of refrigeration. It is next evaporated down until it acquires a density of 40° B. Frank says it cannot be concentrated to the above extent, because of a waste of bromine resulting from the formation of hydrobromic acid produced by the decomposition of the lye, owing to its being overheated at the bottom of the pan. Upon being cooled to 25° C. a quantity of chloride of magnesium crystallises out, whilst the remaining liquor contains from 0·3 to 0·5 of bromine as bromide of magnesium. The liquor is then put into a sandstone apparatus such as is used for the preparation of chlorine, and the requisite quantity of manganese and hydrochloric acid being added, steam is poured into the apparatus. After about a quarter of an hour the bromine is evolved in the form of vapour, which becomes condensed by being made to pass through a leaden worm cooled in water, and is finally collected as liquid bromine in Woolff’s bottles.
The crude bromine so obtained is purified by redistillation in glass retorts. It is stated that the sandstone apparatus can be charged six times in 24 hours. In order to free the bromine from the presence of any chloride it is shaken up with a solution of bromide of potassium.