Note 165 — Chapter IV · THE PROTO-CHALCITIC OR COPPER AGE OF WEAPONS.
Reading edition
Cieza de Leon (Introd. p. xxviii.): ‘Humboldt mentions a cutting instrument found near Cuzco (‘the City’) which was composed of 0·94 parts of copper and 0·06 of tin. The latter metal is scarcely ever found in South America, but I believe there are traces of it in parts of Bolivia. In some of the instruments silica was substituted for tin.’ The South American tin is mostly impure; still it was and can be used.