Note 26 — Chapter I · The Stone Age: its Duration and its Place in Time.

Prehistoric times are generally divided into three epochs—the Stone Age, the Bronze Age, and the Iron Age. We owe this classification to the archæologists of Northern Europe.26 It is neither very exact nor very satisfactory, and fresh discoveries daily tend to unsettle it.27 Alsberg maintained that iron was the first metal used, founding his contention on the scarcity of tin, the difficulty of obtaining alloys, and on the sixty-one iron foundries of Switzerland which may date from prehistoric times. The rarity of the discovery of iron objects, he urged, is accounted for by the ease with which such objects are destroyed by rust. There has never been a Bronze or an Iron age in America, so that it would seem very doubtful whether all races went through the same cycles of development. I myself prefer the division into the Palæolithic period, when men only used roughly chipped stones, and the Neolithic period, when they carefully polished their stone weapons. “There may,” says Alexander Bertrand,28 “be one immutable law for the succession of strata throughout the entire crust of the earth, but there is no corresponding law applicable to human agglomerations or to the succession of the strata of civilization. It would be a very grave error to adopt the theory according to which all human races have passed through the same phases of development and have gone through the same complete series of social conditions.”