THE KING OF METALS. 125 



KING OF" 



IRON AND ITS GEOLOGY. 



THE most useful of the metals is most abundant and most 

 universal. Iron is found in formations of every age, from 

 the Laurentian of the Eozoic to the Quaternary and even the 

 bogs which are forming in the age of man (Compare Talk V.) 

 As Iron has its innumerable uses wherever man makes his 

 dwelling on the earth, so Providence has distributed the metal 

 to all communities. It may be of interest to point out the 

 fact that we find iron most useful, not because most abundant 

 and most accessible, but because its properties give it preemi- 

 nent superiority. Gold and silver and platinum are wanting 

 in the hardness and rigidity which suit iron to many of its 

 most important adaptations. Neither of these metals could 

 be made into useful rails for the steam train to move on. 

 Neither would furnish a tool having the edge and temper of 

 fine cutlery. Iron has been brought so universally into sub- 

 servience to human wants, not because it is available, but be- 

 cause it is at once most suitable and most available. The wide 

 applications of iron are not the outcome of any fortuitous cir- 

 cumstances, but a result of coordinations planned in the con- 

 stitution of things. 



Iron is almost universally disseminated, as a constituent, 

 through the rocks and minerals. It sometimes imparts a 

 black, and sometimes a red or yellowish color; and many 

 times its presence is unannounced by any color. This red soil 

 which, in some regions, prevails extensively, is colored by 

 iron. This red sandstone is colored by iron, this red shale, 

 this red brick like this red rust on the stove-pipe. This yel- 

 low precipitate in the bottom of the stream is the same with 

 water in combination. These are oxides. Now please, don't 

 be impatient at the mention of a chemical term. They hold 

 all the oxygen which the iron can take, and hence they are 

 called peroxides. But the yellow oxide holds water also, and 

 hence is known as a hydrated peroxide. Now follow this hy- 

 drated peroxide this yellow ocher down to the bog which the 



