384 THE POPULAR SCIENCE MONTHLY. 



of which we have just spoken, were discovered by M. Nordenskiold. 

 The discussions upon their origin, which we hesitated at first to regard 

 as terrestrial, sufficed to bring out the close analogies between them 

 and the meteorites. The study of the latter bodies has, then, permitted 

 us to penetrate by induction into the internal constitution of our globe, 

 as if by a side-look into depths wholly inaccessible to direct observa- 

 tion. The last demarkation has thus been effaced, and a most inti- 

 mate connection has been established between the masses thrown up 

 from the interior of our planet and the celestial masses of which the 

 meteorites bring us the fragments. 



The analogies which we have pointed out between meteorites and 

 the profound regions of our globe testify to the identity of the chemi- 

 cal actions, even in the formation of stars very distant from each other. 

 In fact, a mineral generally suggests, in a precise manner, the circum- 

 stances under which it originated. We might say that in itself it 

 tells the story of its origin, especially when it can be reproduced ex- 

 perimentally. We thus perceive how reason, assisted by experiment, 

 can give us clews to the formation of the stars of which we possess 

 fragments. Silica or silicic acid is a chemical agent, the energy of 

 which becomes very considerable at high temperatures ; it is also the 

 characteristic element of numerous products formed in industrial fur- 

 naces, like glass, scoriae, and slags, and of the lavas of volcanoes. All 

 the silicates, artificial and natural, when free from water, or in the an- 

 hydrous state, denote the dominance of a high temperature over their 

 formation. 



Suppose that silicon and the metals were not originally combined 

 with oxygen as they are now, either because the different elements 

 were not near enough together in the primordial chaos, or their tem- 

 perature was not high enough to permit them to enter into combina- 

 tion. When oxygen comes into action, it unites at first with the 

 elements for which it has a predominant affinity, primarily silicon and 

 magnesium, then iron and nickel ; and, if the gas is not in excess, it 

 leaves a residue composed of the less oxidable bodies. Iron and nickel 

 would in that case be left in a free state, disseminated among the stony 

 silicates. This is exactly what is observed in the meteorites ; and it 

 is also a fact which I have confirmed by experiment. By producing 

 the conditions that have just been mentioned, I obtained an imitation 

 in essential points of meteorites of the common type, with the produc- 

 tion of a silicate of magnesia and protoxide of iron, having exactly the 

 constitution of peridote. 



Furthermore, one of the best-known every-day metallurgical opera- 

 tions, the decarbonization of cast-iron, or its transformation into mal- 

 leable iron or steel, gives an analogous reaction and ends in a result of 

 the same kind. Whether the process be carried on in little charcoal- 

 furnaces, as in antiquity, or in puddling-furnaces, or, as by the Besse- 

 mer process, without the addition of any combustible, it is always the 



