The action of water on these alloys just referred to has been recently demonstrated on a larger scale, 5 to 6 cubic centimeters of hydrogen having been obtained in 20 minutes from 2 cubic centimeters of the filed tin alloy. The bismuth alloy yielded more hydrogen than the tin alloy, and the magnesium alloy more than the bismuth alloy. The oxygen of the decomposed water unites with the aluminum. Larger quantities of hydrogen are obtained from copper-sulphate solution, apart from the decomposition of this solution by precipitation of copper at the expense of the metal alloyed with the aluminum. The alloys of aluminum with zinc and lead do not decompose pure water, but do decompose the water of copper-sulphate solution, and, more slowly, that of zinc-sulphate solution.

Aluminum is a metal whose properties are very materially influenced by a proportionately small addition of copper. Alloys of 99 per cent aluminum and 1 per cent of copper are hard, brittle, and bluish in color; 95 per cent of aluminum and 5 per cent of copper give an alloy which can be hammered, but with 10 per cent of copper the metal can no longer be worked. With 80 per cent and upward of copper are obtained alloys of a beautiful yellow color, and these mixtures, containing from 5 to 10 per cent of aluminum and from 90 to 95 per cent of copper, are the genuine aluminum bronzes. The 10-per-cent alloys are of a pure golden-yellow color; with 5 per cent of aluminum they are reddish yellow, like gold heavily alloyed with copper, and a 2-per-cent admixture is of an almost pure copper red