354 Scientific Intelligence. 



,that metal was not attacked, and the bromine retained its properties. Lamp- 

 black, under the same circumstances, had no effect on this body. 



On bringing together iron filings, water, and bromine, the mixture ac- 

 quires an increase of temperature, and proto or deuto-bromuret of iron is 

 formed according to the proportions employed. 



A very pure bromuret of potassium may be procured by pouring a solu- 

 tion of caustic potash into the alcoholic solution of bromine until the alco- 

 hol begins to lose its colour. This salt, evaporated to dryness, and heated 

 to redness, becomes dark. 



The bromuret of silver dissolves easily in ammonia. This solution, on 

 standing for some time, yields white brilliant crystals, which give out am~ 

 monia when heated, and leaves bromuret of silver as a residue. 



2.521 grains of very pure bromuret of potassium yielded by decomposi- 

 tion, with nitrate of silver, 4.041 grains of the bromuret of silver. This 

 result makes the weight of an atom of bromine 94.11, oxygen being taken 

 as 10. 



Nature of Bromine.'— Though the facts stated in the preceding paper, 

 as well as those observed by M. Balard, are favourable to the supposition 

 of bromine being elementary, the real nature of this curious substance is 

 as yet by no means ascertained. M. Chevreul is said to have announced 

 to the Academy of Sciences on the 10th of October, that M. Dumas had dis- 

 covered a chloride of iodine which has all the properties of bromine. — 

 Ferussac's Bulletin des Sciences for December 1826. 



21. On an Analytic Process for separating Iron and Manganese. By M. 

 Quesneville Junior. — The process of M. Quesneville, described in the 

 Journal de Pharmacie for September 1826, consists in bringing the iron, 

 by means of a current of chlorine, to its maximum of oxidation, render- 

 ing the liquid exactly neutral, and precipitating the iron by the arseniate 

 of potassa. The arseniate of the peroxide of iron subsides, while the 

 whole of the manganese is held in solution. The oxide of manganese 

 may then be precipitated by caustic potash. We agree with M. Ques- 

 neville, that the separation of the metals may be effected in this way, pro- 

 vided no free acid is present; but we do not believe his process is at all 

 preferable to that in common use by succinic acid. The per- succinate 

 of iron is indeed decomposed by hot water ; but if cold water only is em- 

 ployed, the whole of the iron will be separated. 



22. Proto- Ferrocyanate of Iron. — Mr Phillips states, that a solution of 

 the protoxide of iron, without any admixture of peroxide, may be obtained 

 by putting the metal into an aqueous solution of sulphurous acid, and suffer- 

 ing the mixture to remain for a short time, without the contact of atmo- 

 spheric air. When a solution of the ferrocyanate of potash is added, a per- 

 fectly white precipitate is formed, which is the proto-ferrocyanate of iron. 

 The action of sulphurous acid upon iron is also remarkable on another ac- 

 count, viz. that no gas is evolved during the solution of the metal, if made 

 to take place in closely stopped bottles. It appears that a part of the sul- 

 phurous acid is decomposed by the nascent hydrogen of the water, and 



