The author placed on the table a battery of four pairs, each consisting of a rod of coke 2½ inches long by 1½ in diameter, surrounded by a cylinder of amalgamated zinc, 2½ inches high by 2¼ inches in diameter; the different pairs were firmly attached to the same bar of wood, and could be immersed in jars of stoneware at once. The arrangement was charged with a mixture of nitric acid one part, sulphuric acid four parts, water eight parts. The author stated that he considered the power of the battery, which was twice that of Grove's, was due to the heat generated on the surface of the zinc by the local action of the nitric acid.