88 THE POPULAR SCIENCE MONTHLY. 



stony ores. The myths of different nations generally indicate a god 

 or a hero as the inventor of metallurgy ; but it is now hardly doubt- 

 ful that this god was in most eases a human mind directed by some 

 accident. 



Tin, iron, and the other metals, as we have said, do not occur pure, 

 but as oxides in stone. They have a strong affinity for oxygen, and 

 can not be separated from it and produced in a metallic condition, ex- 

 cept by the aid of powerful reagents. There is one element which has 

 a stronger affinity for oxygen than any metal — glowing charcoal, which, 

 in the contest with the metallic oxide, wrests the oxygen from it. In 

 the innumerable places where the primitive man — hunter, fisher, or 

 nomad — built his fires, there can not have failed to be some where the 

 red-hot coals would lie upon a soil containing ores. This would be 

 sufficient to reveal the metallic treasure. By the occurrence of acci- 

 dents of this kind, men learned to recognize the metal, and in a similar 

 way how to extract it from the earth. 



Of the two hard metals we have named, bronze came earlier into 

 use, while the fabrication of iron belongs to a later period of civiliza- 

 tion. It has been thought strange that bronze, a compound of two 

 constituents, should have been got and used earlier than the simple 

 metal, iron. And it has been objected that the former product is gen- 

 erally too soft to be valuable for weapons and tools, that pure copper 

 is hard to get, and that tin-ore occurs in only a few places. All of 

 these objections must yield to historical facts ; and they can not be 

 upheld against opposing geological considerations. First, it is not true 

 that an alloy is harder to produce than a single metal. Man must in 

 the beginning have melted up together the ores of different kinds as 

 they occurred associated in nature, and thus have obtained a variety 

 of alloys. Among others, cojDper and tin ores occur near each other 

 in several regions. In such places bronze would have been produced, 

 at first accidentally, afterward on purpose. In other places, where 

 these metals are not naturally associated, one or the other of the con- 

 stituents, or perhaps the alloy already formed, had to be imported. The 

 second objection is no less fallacious : if substances containing phos- 

 phorus are melted up with the ores, the resultant product will have 

 considerable hardness, which may be increased by repeated tempering 

 and hammering. The third objection rests on observations in the most 

 famous copper districts of Europe. It must be remembered in respect 

 to the mines of these regions, that the operations have been carried on 

 for a long time at a great depth, where the sulphurous copper-ores are, 

 it is true, very hard to utilize. But in former times the ores lay nearer 

 to the surface, and they were, in the degree that they were exposed, 

 purified and made more reducible by atmospheric agencies. Oxides, 

 carbonates, and pure copper were to be found. They were easy to 

 smelt, and gave a pure product. It must also be remembered that tin 

 was not so scarce in the earliest times as it is now ; and there are still 



