Chemical Science. 389 



When peroxide of iron was thus cemeialed, simihar and other 

 interesting results were obtained. When the mass was not large, 

 so long as red oxide remained at tlie centre, no metallic iron was 

 produced at the surface, but only black oxide. After a sufficient 

 length of time, magnetic oxide only was found at the centre, and 

 iron appeared at the surface. It appears, that the peroxide is first 

 changed into magnetic oxide, and as soon as that has taken place, 

 the reduction is propagated from the surface to the centre, so that 

 whilst metallic iron is forming at the surface, the deutoxide (or 

 scales) is forming in the interior even to the very centre ; and that, 

 ultimately, even a layer of steel is produced at the surface. 



Then arises the question, how are these effects produced ? How 

 is it that the oxide is reduced without any contact of carbon? To 

 prove that it could not be occasioned by the percolation of the 

 vapours of the furnace through the porous mass of oxide generally, 

 various experiments were tried with the charcoal in different parts 

 of the mass; the effect was always found to commence at the char- 

 coal and proceed from it. 



The oxidation of iron to the depth which takes place in cases 

 where the metal is heated for a long time, is to M. Berthier as 

 inexplicable as the case of reduction ; for he remarks, as soon as a 

 coat of oxide is formed, it protects the iron from further contact of 

 air like a varnish; and it must therefore be admitted, that the iron 

 attracts the oxygen through the oxides, just as the oxides attract 

 the carbon through the metallic iron. — Aim. de Chhnie, xxvii. 24. 



Analysis of Meteoric Stones and Iron found in Poland. By M. 

 Laugier. — The specimens examined were received by M. Brong- 

 niart from M. Horadecki, of Vilna; they had fallen at different 

 times in Poland, and M. Laugier found them perfectly consistent 

 in their results with the results he had obtained from other aerolites. 

 He first describes the general mode of analysis, which appears to 

 him most applicable to these bodies: this consists of two processes, 

 one by alkali, the other by acid — fuze in a silver crucible 100 parts 

 of the aerolite and 400 hydrate of potash ; dissolve in water, allow the 

 solution to settle, decant and wash the insoluble portion with hot 

 water. The solution will contain oxide of manganese, chromate of 

 potash, silica, and a little alumina: if it be green boil until yellow, 

 filter and collect the deposit. Concentrate tlie solution to one half, 

 supersaturate with weak nitric acid, precipitate by protonitrate of 

 mercury, leave it to settle, decant the liquor and put the deposit 

 into a crucible ; wash it with water until it has no taste, dry the 

 precipitate, calcine it, and weigh the oxide of chrome. Evaporate 

 the decanted solution, heat to briglit redness, re-dissolve in water, 

 and the silica and alumina will be left, which may be separated in 

 the usual way. 



The moist portion insoluble in the alkali, is to be dissolved in mu- 



