Pure nickel foil, obtained in Paris by Dr Andrews, was cut into spiral about 20 inches long, and it was on this spiral that all the following experiments were made. During the month of November 1875 a large number of experiments were made as to its thermoelectric properties, and these were found to be almost identical with that of the specimen from observations on which the line was laid down on the “thermo-electric diagram.” (Trans. R.S.E., 1872–3.) This line, it will be remembered, is a peculiar one, and is very similar to that of iron, with this difference, that the peculiar changes take place at much lower temperatures in nickel than in iron.