1822.] Separation of Iron from other Metals. 99 



ture by carbonate of ammonia, and the iron separated, a green 

 solution remained. Into this, when boiling, a drop of persul- 

 phate of iron being let fall, was immediately precipitated in the 

 state of subsulphate, which, being separated, the solution was 

 boiled with excess of caustic potash till all smell of ammonia 

 disappeared. Oxide of nickel separated, which, collected and 

 strongly ignited, weighed 4-65 grains, or 12*92 on the hundred, 

 which (taking the atom of nickel to weigh 30, and that of oxy- 

 o-en 8, hydrogen being unity) gives 10'20 per cent, for the con- 

 tents of the specimen analyzed in metaUic nickel. 



100 grains of titanious iron from North America, being dis- 

 solved in muriatic acid (after the requisite ignition with potash) 

 were treated (after separating the titanium) with excess of car- 

 bonate ofhme, and filtered. The excess of carbonic acid being- 

 expelled, ammonia was added, and a small quantity of a white 

 precipitate fell, which speedily blackened in the air, and proved 

 to be mere oxide of manganese, uncontaminated by iron, and 

 amounting to half a grain. 



Manganese has been suspected in various species of cast iron; 

 and though Mr.Mushet's experiments go to prove that it does not 

 •usually enter in abundance, they can hardly be regarded as esta- 

 bhshing the fact of its absence. It might not be uninteresting 

 to resume the investigation with the aid of a mode of analysis so 

 well adapted to experiments on a large scale, as I have no doubt 

 that, with proper care, one part in a thousand, or even less, of 

 manganese might be insulated from iron. 



The separation of iron from uranium cannot be accomplished 

 by the process above described, that metal possessing a property 

 analogous to that which forms the subject of this paper. By 

 inverting the process, however, we shall succeed even here. A 

 mixed solution of iron and uranium being deoxidized by a cur- 

 rent of sulphuretted hydrogen, and then treated with an earthy 

 carbonate, the iron passes in solution, while the uranium sepa- 

 rates. This difference in the habitudes of the two oxides of iron 

 presents us in fact with a kind of chemical dilemma, of one or 

 the other of whose horns we may avail ourselves in any proposed 

 case. In studyii/g the habitudes of uranium, however, I have 

 met with some anomalies which require further investigation. 

 Zirconia too might probably be freed from iron with equal faci- 

 lity by a similar inversion of the process ; but this I have not 

 yet had an opportunity of trying satisfactorily. 



J. F. W. Herschel. 



h2 



