180 Scientific Intelligence. 



And hence, supposing it to contain one atom of each element, the weight 

 of an atom of brome will be represented by 9.326, that of oxygen being re- 

 garded as unity. 



Ammoniacal gas unites with its own volume of hydro-bromic acid gas, 

 forming a white, solid, volatile salt, which is soluble in water, and crystal- 

 lizes in long prisms by evaporation. 



The hydro-bromate of baryta is very soluble in water, and is also dis- 

 solved by alcohol. It forms opaque mamillated crystals, which have no 

 resemblance to the transparent scales of the muriate of bary tes. 



The hydro-bromate of magnesia is deliquescent and uncrystallizable, and, 

 like the muriate of that base, is decomposed by an elevated temperature. 



On mixing a soluble hydro-bromate with the nitrate of lead, silver, and 

 the protoxide of mercury, white precipitates are obtained, which are very si- 

 milar to the chlorides of those metals, and which appear to be metallic bro- 

 murets. By the action of brome on metallic mercury, a compound results 

 which yields the peroxide of mercury when decomposed by alkalies, and 

 must therefore be a bi-bromuret. It may be sublimed by heat, is soluble 

 in water, alcohol, and ether, particularly in the last, and presents a close 

 analogy to corrosive sublimate. It is distinguished from that substance, 

 however, by yielding the red vapours of brome when treated by the nitric, 

 and still better by the sulphuric acid. 



The bromuret of silver has the same curdy appearance as the chloride, 

 blackens by exposure to light, is soluble in ammonia, and insoluble in 

 nitric acid ; which does not decompose it even at a boiling temperature. Boil- 

 ing sulphuric acid, on the contrary, detaches some vapours of brome. The 

 bromuret of silver is decomposed by hydrogen in a nascent state, and was 

 found by M. Balard to consist of 



Silver, - - 589 



Brome, - - 411 



1000 

 The atomic weight of brome, estimated from these data, is 9.429. 

 Brome acts upon metallic oxides much in the same manner as chlorine. 

 On passing the vapour of brome over potassa, soda, baryta, or lime, a vivid 

 incandescence ensues, oxygen is disengaged, and a metallic bromuret re- 

 sults. Magnesia and zirconia are not decomposed by this treatment. 



When brome acts on the solution of an alkali or alkaline earth, consi- 

 derably diluted with water, the bromuret of an oxide is produced, which 

 possesses bleaching properties, and from which acetic acid causes the dis- 

 engagement of brome. But when this substance acts upon a concentrated 

 solution of potassa, or when solid potassa is agitated with the ethereal solu- 

 tion of brome, two salts are generated, the hydro-bromate and bromate of 

 potassa ; and on evaporating the solution, the former is obtained in cubic, 

 and the latter in acicular crystals. The bromate of potassa is separated from 

 the hydro-bromate by being very sparingly soluble in cold water. The 

 alkaline earths likewise cause the formation of the two acids, but magnesia 

 does not appear to possess that property. 



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