Itf4i ' Intelligence a?id Miscellaneous Articles. 



The bromide of barium when dissolved, serves for preparing by 

 double decomposition the bromides of magnesium and zinc, by em- 

 ploying the sulphates of these bases. 



BROMIDE OF POTASSIUM. 

 This is prepared by decomposing protobromide of iron with car- 

 bonate of potash ; when the saturation is perfect, the mixture is to 

 be heated in the air to facilitate the peroxidation of the iron ; the 

 solution is to be filtered and evaporated, and by one or two crystal- 

 lizations the pure bromide is obtained. 



This salt crystallizes very well in cubes ; it has a slightl)' saline 

 taste, is slightly alterable by exposure to moisture, is soluble in 

 alcohol, is decomposed by sulphuric acid, like the bromides of cal- 

 cium and barium, and fuses without decomposing. When decom- 

 posed by sulphuric acid and heat, a portion of sulphate of potash 

 was obtained, which showed it to be composed of 



Potassium 26'5'i8 



Bromine l'6-^o2 



100 

 BROMIDE OF SODIUM. 

 Obtained as the last, substituting carbonate of soda for that of 

 potash. This bromide crystallizes very well in groups of small 

 acicular crystals, of a whitish colour. It slightly attracts moisture 

 by exposure to the air ; its taste is rather alkaline than saline, and 

 it is very soluble in water and alcohol. 



It is composed of Sodium 1338 



Bromine 8662 



100 

 Journ, de Pharmac. Feb. 1829. 



PROTOBROMIDE OF MERCURY. 



Pour a neutral solution of bromide of potassium, calcium, or mag- 

 nesium, &c., into a very dilute solution of protonitrate of mercury; 

 an abundant flocculent precipitate is formed, which is of a yellowish 

 white colour : when this is carefully washed, and dried in the shade, 

 the residue may be volatilized by a strong heat, and it condenses in 

 the state of an acicular crystalline mass, which is of a yellowish 

 colour while hot, but becomes whiter on cooling. It fuses like the 

 protochloride and perchloride of mercury. Reagents, such as potash, 

 soda, and the hydrosulphurets, precipitate this bromide in the state 

 of mercurial protosalts. 



It is probably composed of Mercury . . 57'36 

 Bromine . . 4'2*64< 



100 



PERBROMIDE OF MERCURY. 

 This compound may be prepared directly as proposed by M. 

 Balard, by treating mercury with bromine, and subliming,or by decom- 

 posing persulphate of mercury with very dry bromide of potassium 



with 



