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alumina in equal, and iron, lime, and magnesia in much larger pro- 

 portions, with also a great variety of other elements as occasional 

 constituents ; while the denser metals are in larger proportion in 

 the more central portion of the nucleus. The suggestion of Mr. 

 Lockyer is that the order follows necessarily from the original 

 localization of the earths and metals before referred to, by 

 which the oxygen, silicon, and other metalloids formed, as tbey 

 now do in the sun, an outer atmosphere, succeeded by an inner one 

 consisting in greater part of the alkaline earths and alkalies, then 

 by a lower one of iron and its associative gi-oup of metals, and 

 finally by an inner nucleus containing the other and denser metals." 



One thing which distinguished iron from all other metals was 

 its almost universal diffusion through the rocks of the earth. It 

 was difficult to open our eyes out of doors and not see some tint 

 which was due to its presence. It was, in fact, the great colouring 

 matter of nature. It gave the redness to the bricks of which our 

 houses were built, and the dark purple to the slates of our roofs. 

 The amber tint of the sands on the sea shore was due to it, and 

 the ruddy hue of the newly-ploughed field. All the many shades 

 of yellow, brown, and red, which gave that picturesque tint to tlie 

 great rock masses of the earth, were imparted by iron, as well as 

 the scarlets and crimsons of agate, bloodstone, and Cornelia. 

 Finally, if the red colour of the blood be not entii-ely due to iron, it 

 was in some manner intimately associated with it. And yet, not- 

 withstanding its almost universal diffusion, there were few things 

 more rare than a specimen of pure iron. A piece of fine pianoforte 

 wire was as free from impurities as iron was generally made. Thanks, 

 however, to the kindness of W. C. Roberts, Esq., the Chemist to the 

 Royal Mint, he had the pleasure of showing them that evening, one 

 of the very few specimens there were in the world. This was obtained 

 by electrolysis. On the table they would also see a fine specimen 

 of a meteor that fell in Mexico, in which the iron was tolerably 

 pure. 



This metal, then, not being known to us native, in what 

 combinations did it principally present itself to us. Generally 

 speaking, in union with oxygen. With this gas it combined in 

 several proportions. The three principal ones were, one of iron and 

 one of oxygen, two of iron and three of oxygen, and three of iron 

 and four of oxygen. When a mass of rock contained as much as 



