The chlorine unites with the potassium, forming chloride of potassium and liberating an equivalent quantity of bromine in so doing. Dr Frank suggests the use of earthenware worms in preference to leaden ones, these latter being acted upon and corroded by liquid bromine. In Dr Frank’s bromine works at Stassfurt the distillation is conducted in cubic stoneware vessels, having a capacity of about three cubic metres. These vessels are surrounded with belts of iron, in case of the occurrence of fracture. It was found that few stones answered the purpose required of them, as by reason of their porous nature they permitted the chloride of manganese formed during the distillation to ooze through. To remedy this the stones had to be coated with tar, a process which entailed a very serious loss of bromine, from the formation of bromine compounds with the hydrocarbons of the tar, as well as a contamination of the bromine with the tar. Subsequently Dr Frank found in the neighbourhood of Porta Westphalia a stone which answered the purpose without requiring the previous objectionable and expensive preparation with tar.
It seems that the workmen discard the respirators which are provided for their use in the bromine works, and merely tie a cloth over the mouth and nose (sometimes neglecting this precaution) when decanting the bromine.
To lessen the evil effects of the vapours upon the health of the workmen under these circumstances, the building is rendered as airy as possible by being thoroughly ventilated throughout. No workmen afflicted with asthma or with any catarrhal affection are employed, whilst those engaged are strictly prohibited from taking spirituous liquids in any form, a custom which begets an irritability of the mucous membranes, which is found to be exceedingly dangerous; on the contrary, a generous diet, and one consisting of an abundant use of bacon and butter, was found very beneficial.
Bromine is sometimes contaminated with chlorine, iodine, and occasionally bromide of carbon. A small quantity of the bromine agitated with a solution of soda, in such proportion that the fluid is made very slightly alkaline, forms a colourless solution, which, if coloured by the further addition of a small quantity of the bromine, does not become blue on the subsequent addition of a cold solution of starch. This shows the absence of iodine. Chlorine may be detected by adding a small quantity of the suspected bromine to some warm solution of potash in a capsule, evaporating, drying the residue, and distilling with bichromate of potash and sulphuric acid. Bromide of carbon has a higher boiling-point than pure bromine.
Prop., &c. A dark, reddish-coloured, volatile liquid, having an odour intermediate between that of chlorine and iodine, but much more suffocating and offensive. It solidifies at about 19°, and boils at about 145° Fahr. It is slightly soluble in water, more so in alcohol, and abundantly so in ether. Its aqueous solution bleaches like chlorine, but less powerfully. With hydrogen it forms HYDROBRO′MIC ACID; and with the bases, compounds called BRO′MIDES. Its sp. gr. is 2·976; that of its vapour, 5·39.
Tests. It is readily recognised by its colour, odour, and volatility, and by the colour
of its vapour; by its giving a yellowish-white precipitate with nitrate of silver, which is turned violet by the action of light; and by its solutions giving an orange or yellow colour to starch, and a red tinge to solution of chloride of gold.
Uses, &c. Bromine possesses very similar medicinal properties to iodine, and has been administered in goitre, scrofula, &c., in the form of an aqueous solution composed of 1 part of bromine to 40 of water, of which 5 or 6 drops is the dose; but it is more usually given under the form of bromide of potassium (which see). The compounds of bromine are also largely used in photography in the manufacture of certain coal-tar colours, and in scientific chemistry the solution has also been used as a lotion. Bromine is a good disinfectant. It is very poisonous; the antidotes, &c., resemble those for iodine. See Bromide, Solutions, &c.
BROMOCHLORALUM (Tilden & Co., New York), for the removal of bad smells, as a disinfectant, and antiseptic. A fluid, sp. gr. 1·43, containing 27·5 per cent. of solid matter. The latter consists of 18·5 per cent. of aluminium chloride, with chalk and a considerable quantity of alkaline salts. Free bromine is not present. (H. En{?}demann.)
BROMOFORM (CHBr3). A colourless liquid obtained by distilling bromide of calcium with alcohol. It has a sp. gr. of 2·90; and boils at 305·6° F., emitting a vapour having a density 8·632. It is somewhat similar in properties to chloroform, but much more irritating; hence it has been rarely employed medicinally.