On the physiological and medicinal properties of bromine and its compounds; also on the analogies between the physiological and medicinal properties of these bodies, and those of chlorine and iodine, with their correspondent compounds / [Robert Mortimer Glover].

  • Glover, Robert Mortimer, 1816-1859
Date:
[1842]
Catalogue details

Licence: Public Domain Mark

Credit: On the physiological and medicinal properties of bromine and its compounds; also on the analogies between the physiological and medicinal properties of these bodies, and those of chlorine and iodine, with their correspondent compounds / [Robert Mortimer Glover]. Source: Wellcome Collection.

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    those of iodides of the same bases.* The three elements all un¬ dergo modifications of form by slight changes of temperature and pressure. Chlorine becomes a liquid under the comparatively slight pressure of four atmospheres. Bromine, which freezes at 10°, boils at 116° 5', and iodine is melted and volatilized by a slight elevation of temperature. Even the chemical equivalents of the elements exhibit the same traceable connection ; the equivalent of bromine being nearer that of chlorine than it is to the equivalent of iodine. And passing from chlorine to bromine and iodine, we find their affinity for elec¬ tro-positive bodies represented by hydrogen to decrease, while the affinity for electro-negative bodies represented by oxygen increases, which may be illustrated under the following heads : 1. Bromine does not, like chlorine, combine directly with hy¬ drogen under the influence of solar light, although a small quan¬ tity of a mixture of bromine and hydrogen may be made to unite on introducing a red hot wire. It is still more difficult to com¬ bine iodine directly with hydrogen.-f c2. Nitric acid decomposes all the three liydracids, but the hy- drobromic and hydriodic acids are decomposed likewise by sulphu¬ ric acid. 3. Chlorine and bromine act more powerfully on organic mat¬ ters than iodine, which pre-eminence they appear to owe to their greater affinity for hydrogen ; they rapidly act upon alcohol, giv¬ ing rise to the production of chloral and bromal, while iodine may be kept long in this fluid, before much effect ensue. 4. Iodine being more electro-positive than the other two ele¬ ments, does not in every case dispossess oxygen from an electro¬ positive metal, which may be the reason why, in some cases, it forms iodides of oxides, where they create bleaching compounds.]; 5. Chloride of iodine and chloride of bromine are decomposed by alkaline solutions, with formation respectively of a hydrochlo¬ rate and iodate, and hydrochlorate and broinate, but the bromide of iodine is so decomposed with the result of a hydrobromate and iodate being obtained. Under the same head may be placed the difficulty of concentrating chloric and bromic acids on account of their tendency to decomposition, while iodine holds its oxygen more tenaciously. * Ann. de Chimie, T. i. serie iii. t Balard, Ann. de Chimie, T. xxxii. £ I have observed a fact with regard to the action of bromine on one metallic oxide, which I have not seen noted. When solution of bromine in water is added to solution of nitrate of oxide of silver, a precipitate is formed, and the solution acquires the smell characteristic of the bleaching compounds of chlorine. On filtering the solu¬ tion, it yields a further precipitate after filtration, and bleaches strongly and conti¬ nues to furnish more precipitate for several days. The nature of the action is doubt¬ less similar to that of chlorine on solution of nitrate of silver, or on red oxide of mer¬ cury. A hypobromous acid or a bromous acid must be formed.