MAN is a tool-shaping animal. He alone infuses matter with purpose, and so makes it effective for widening and strengthening his wonderful dominion over physical nature. What is more, his thoughts themselves grow with the means at his command, and their growth in turn inspires a further restless seeking after instruments of fresh conquests. The first metal-workers, accordingly, crossed a gulf destined to divide the ages. It was not for nothing that legendary honours were paid to them; they were the vague recognition of a really momentous advance. Its importance consisted, not so much in the immediate gain of power, as in the implication of what was to come. For metallurgy is an art which does not easily stand still. Even in its crudest stages it demands some technical skill; and technical skill cannot be attained without division of labour, differentiation of classes, and development of intelligence by its direction into special channels, and towards feasible ends. There are, then, few better tests of civilisation than the degree of command acquired over the metals. The wide compass of metallic qualities was in itself stimulating to ingenuity. There was always something new to be found out about them, and they lent themselves with facility to every variety of treatment. This versatility contrasted strongly with the rigid and impracticable nature of the stony substances they tended to supersede. Thus, the six primitive metals not only presented, at first sight, a great number of diverse characteristics, but those characteristics proved, on the most elementary trials, highly susceptible of change. They could be surprisingly modified, for instance, by mutual admixtures, and, in a lesser degree, by differences of manipulation. Secrets of the craft hence multiplied, and invited, as they continue to invite, further experiments and research. Of still greater consequence to civilisation at large was the comparatively recondite occurrence of the metals. They are not to be met with, like flints or pebbles, strewing the bed of every stream; their distribution is defined and restricted. The demand for them could, for this reason, only be supplied by opening long lines of communication; it led to extended intercourse between nations, and created wants stimulating to traffic.