IM Miscellaneous Intelligence, 



and strontia is very soluble in excess of acid. On this difference 

 in properties, M. Berzeiius founds a process for the separation of 

 these two earths : he considers it an easy one and sufficiently exact 

 for the estimation of their quantity. The mixture of the two 

 earths is to be dissolved in muriatic acid, then solution of silicated 

 fluoric acid is to be poured in, the baryta will precipitate, and its 

 weight is determined by that of the precipitate ; a very minute 

 quantity of sulphuric acid added to the solution, will precipitate 

 the rest of the baryta without acting on the strontia. The liquid 

 is to be filtered : evaporated to dryness, and the residue decom- 

 posed by sulphuric acid. — Ann. de Chimie. xxvii. 301. 



12. On Combinations of Carbon and Iron^ Pig Iron, &c. — A long 

 experimental memoir by M. Karsten, on the combination of iron 

 and carbon, is contained in the Annales des Mines, ix. 657. We 

 have not time at present to analyze it, but give the results as drawn 

 up by the author, and appended to the memoir. 



1. White cast iron and tempered steel contains the carbon com- 

 bined with the whole mass of iron. 2. Lamellated white cast 

 iron presents a perfect combination of iron with carbon ; it always 

 contains more carbon than the grey cast iron. 3. Iron and steel, 

 jiot tempered, contain the carbon in the state of carburet. 4. 

 Cold grey cast iron contains the larger part of its carbon, in the 

 state of graphite and of mixture : this graphite contains no iron, 

 but constitutes the carbon in all its purity. 5. The rest of the 

 carbon <3ontained in the grey cast iron, may be found either com- 

 bined with the whole mass, or forming a definite carburet, which 

 is afterwards dissolved in the metal, as is the case with soft iron, 

 or steel. 6. All the varieties of carburetted iron, considered in 

 the liquid state, contain the carbon dissolved in the mass of metal 

 in indefinite proportions. 7. Finally. The graphite separates 

 from the metal at the moment of congelation, and if there be other 

 carburets of iron, they separate at a later period. 



Remarking on the means generally proposed for the separation 

 or estimation of the carbon in carburetted iron, M. Karsten finds 

 grounds of objection to them all. That proposed by M. Vauquelin, 

 namely, the use of sulphurous acid, he states to be uncertain and 

 inaccurate from the formation of sulphuret of iron. 



13. Massive Copper obtained by the Moist Process. — M. Clement 

 has described the production of metallic copper from a solution, in 

 a state as dense and compact as that afforded by fusion. It occurs 

 in the manufactory of M. Mollerat during a process, the object of 

 which, is to prepare sulphate of copper by the calcination of copper 

 with sulphur. A solution of the sulphate is obtained turbid from 

 the presence of insoluble sub-sulphate. This solution is intro- 

 duced into a wooden tank, that it may become clear by deposition ; 



