415 M, Balard on a peculiar Substance [Dec* 



differ much from that deduced from the analysis of the bromuret 

 of potassium. 



Bromuret of Gold, 



Brome and its aqueous solution are capable of dissolving smar 

 portions of gold ; and a yellow bromuret is obtained, staining 

 animal substances of a yellow colour, and decomposable by 

 heat into brome and metallic gold. 



Bromuret of Platina, 



Platina is not acted upon by brome at common temperatures ; 

 but it is dissolved by bromo-nitric acid, and forms a compound 

 of a yellow colour, which is decomposed by heat, and which, 

 like the chloride of platina, produces sparingly soluble yellow 

 precipitates in the solutions of potash and ammonia. 



On the Action of Brome upon Metallic Oxides. 



Brome acts upon metallic oxides under two different circum- 

 stances ; when they are dry and strongly heated, and at usual 

 temperatures with the presence of water. 



If the vapour of brome be passed over potash, soda, barytes, 

 or lime, at a red heat, vivid ignition takes place ; oxygen gas is 

 liberated, and the bromurets of potassium, sodium, &c. are found 

 in the tube. I was unable to decompose magnesia and zirconia 

 in the same manner ; the brome circulated round these ignited 

 earths without either liberating oxygen, or combining with them. 

 Sublimed oxide of zinc underwent no alteration by the action of 

 brome at a high temperature. 



The metallic oxides which brome is capable of decomposing 

 -do not appear susceptible of this alteration when they are com- 

 "bined with a powerful acid ; so that I attempted in vain to libe- 

 rate oxygen by passing brome over red-hot sulphate of potash. 

 When an acid has but little affinity for the metallic oxide, the 

 case is different ; the alkaline carbonates being completely 

 decomposable by brome, which evolves gas consisting of twO 

 volumes of carbonic acid and one volume of oxygen. 



The phenomena are very different when brome is made to act 

 upon the alkalies or earths, already mentioned : when they are 

 -dissolved in or mixed with a considerable proportion of water, 

 no liberation of oxygen gas is observed, the smell and colour of 

 the brome disappear, but a compound is formed from which 

 brome is evolved by weak acids, such as the acetic acid, and 

 "which possesses the property of quickly decolorizing tincture of 

 tournsole. According to these experiments, brome appears to be 

 capable of forming bromurets of oxides, analogous to the chlo- 

 ricfes of lime, soda, &c. 



When brome is mixed with a very concentrated solution of 

 potash, the solution after evaporation yields not only cubic 



