Scientific Intelligence, Sfc. 235 



some earthy oxides, the oxides of copper, mercury and silver are de- 

 composed and by it transformed into bromides, and hypobromites or the 

 bromine is converted into hypobromous acid. The hypobromites are 

 readily converted into bromates and bromides. Thus it appears, 

 that the action of chlorine and bromine upon the metallic oxides is 

 analogous. — Z/'Institut, December, 1834. 



XIV. — Triple Compounds of Osmium, Iridium, and Chloride 

 of Platinum, Sj'c. 



1. Triple Salt of Osmium and Chloride of Iridium, with Chloride 

 of Potassium. — When the natural mixture of osmium and iridium, 

 as it occurs in the Uralian sand, is mixed with chloride of potassium, 

 and heated with chlorine, a combination is found which crystallizes 

 in octahedrons, consisting of iridium 26*6, osmium 13*4, chlorine and 

 chloride of potassium 60*0. 



2. Triple Salt of Iridium and Chloride of Platinum, with 

 3furiate of Ammonia. — This salt is procured in the manufactory 

 of St. Petersburgh, by evaporating the solution from which the 

 platinum has been separated by muriate of ammonia. It consists of 

 iridium 31*76, platinum 10*59, palladium 1*25, chlorine and muriate 

 of ammonia 56*40. 



3. Triple Salt of Iridium and Chloride of Platinum, with 

 Chloride of Potassium. — When a mixture of sesqui-oxide of 

 iridium and platinum-chloride of potassium is digested with muriatic 

 acid, a smell of chlorine is emitted, and a salt crystallizing in octa- 

 hedrons is produced on evaporation. It consists of iridium 8*, 

 platinum 32*, chlorine and chloride of potassium 60*. — Ibid. 



XV . — Carbonate of Iron of Traversella. 



This mineral is accompanied with quartz and pyrites. S. Sismonda 

 endeavours to explain the mode in which the carbonate loses its 

 acid from the presence of the pyrites. The latter decomposess 

 and forms a sulphate of iron with excess of acid. This excess acts 

 upon the carbonate. Neutral sulphate of iron is the result, which 

 is immediately decomposed by the lime, which exists in an isomor- 

 phous state, as it is called. Now, according to the atomic weights 

 of these bases, the lime which in the carbonate re-places part of the 

 iron, is not sufficient to decompose the whole of the sulphate of iron. 

 It is possible, that this excess of sulphate of iron is dissolved by water, 

 or decomposed by earths which come in contact with it, but it is more 

 probable, that the proto-sulphate of iron, decomposes the water to 

 become peroxidized, and that the hydrogen disengaged abstracts a 

 portion of oxygen from the sulphuric acid which then escapes in the 

 form of sulphurous acid. 



He ascertained that the lime exists in the mineral in the state of 

 sulphate, according to his theory. He submitted the carbonate of 

 iron with its natural mixture of pyrites to a gentle galvanic current, 

 after four hours, the carbonate of iron in contact with the pyrites. 



