538 POPULAR SCIENCE MONTHLY. 



niglit of the ages. It has hardly been more than a century since 

 chemists first succeeded in accounting for the reactions and in 

 improving upon them by the aid of more precise notions founded on 

 the theories of modern science; and our own age has witnessed a 

 still more radical transformation in metallurgy resultant upon the 

 discoveries in electro-chemistry. But everything rested, in antiquity, 

 upon empiricism, unguided, except by vague analogies. 



The metals which the ancients thus obtained and made use of 

 were not always pure metals. The ancients had a number of varieties 

 of copper and of lead. First, a distinction was made between black 

 lead and white lead; the first being our modern lead, while the second 

 has become our tin. These names were, however, applied to other 

 metals and alloys, including antimony, which was obtained by roast- 

 ing and reducing its sulphuret, under conditions which are described 

 by Dioscorides; and some alloys of silver originally designated by 

 the name of cassiteros, which was afterward applied to our tin. The 

 stannum of Pliny also has this double meaning. 



The white alloys, of brilliant and little changeable surface, were 

 given a special name — asem, or Egyptian silver — a name which was 

 continually reappearing with the Greek alchemists, and was con- 

 founded with the name of silver without definite title — asemon — 

 a designation which was given to very diverse substances, from pure 

 tin to electrum. So it was with the metal called chalJces in Greek, 

 aes in Latin — a name which included innumerable species; whence 

 modern translators use indifferently the words brass, copper, and 

 bronze to represent it. Modem pure copper is too soft to be used 

 for forging arms or solid tools, and the Greek and Latin names 

 usually refer to alloys. The ancients had copper of different colors, 

 and specified the species by adjectives derived either from these 

 colors, or from the place of origin of the substance. Thus, they had 

 red copper and Cyprian copper, aes Cyprium — an epithet which, 

 in the time of the Roman Empire, became the name of the metal, 

 cuprum — besides yellow copper, white copper, etc. Yellow cop- 

 per in its turn included several varieties, for its composition varied 

 greatly. First, there were the bronzes, alloys of copper and tin, 

 used for many centuries in the manufacture of arms, till they 

 were dethroned by the advances in the manufacture and temper- 

 ing of iron. In the Roman Empire one of these alloys, which 

 was used for mirrors, was designated, after the name of Brin- 

 disium, where the manufacture was carried on, aes Brundusinum, 

 whence our word bronze is derived ; in other alloys of various shades, 

 yellow or whitish, copper was combined with lead or zinc — a metal 

 which the ancients did not know in a state of purity, but of which 

 they were acquainted with the minerals, natural cadmies or calamies 



