The discharge of the voltaic battery had hitherto been considered absolutely continuous; and so it is for chemical action, whether of analysis or combination; nevertheless certain phenomena gave reason to doubt its continuity. Mr. Gassiot has proved that the tension of a single cell of a galvanic battery increases in force according to the chemical energy of the exciting liquid, and in all his experiments he found that ‘the higher the chemical affinities of the elements used, the greater was the development of evidence of tension.’ These observations induced him to institute a series of experiments with galvanic batteries of different chemical affinities, and to compare the resulting phenomena with those produced by the induction coil, whose sparks are of high tension. The same carbonic acid vacuum tubes were made use of in all the experiments; a copper wire formed the positive terminal, and a copper plate was fixed at the extremity of the negative terminal. In other tubes platinum terminals extended into the interior, coated with glass, except the points, to which charcoal balls were fixed. One end of the tubes was of small diameter and contained caustic potash. When a discharge from an induction coil was sent through these tubes, there were either minute luminous spots, narrow stratifications, or a well defined cloud-like discharge at the positive pole, according to the size and structure of the terminal, but the characteristic phenomenon in all the tubes was a large cloud-like luminosity or circular glow on the brass plate or charcoal ball at the negative terminal. With 512 insulated cells of copper and zinc of Daniell’s constant battery, the exciting liquid being dilute sulphuric acid, a brilliant glow appeared round the charcoal ball of the negative terminal on the passage of the electric discharge through the tube, with very trifling luminosity of the positive pole. Two copper plates that could be separated or closed by a screw, were placed between the poles of a nitric acid battery, so that the circuit could be made or broken gradually, and spark discharges were obtained between them. The vacuum tubes were placed between one of these plates and a pole of the battery; one of these tubes was 24 inches long, 18 in circumference, and had a circular copper disc 4 inches in diameter on its negative terminal. On completing the circuit, the discharge of the battery passed with a display of magnificent strata of dazzling brightness; on separating the plates by the screw, the luminous discharges presented the same appearance as when taken from an induction coil, but brighter. On the copper disc within the vacuum tube, there was a white layer, then a dark space about an inch broad, and then a bluish atmosphere curved like the disc, evidently three negative envelopes on a great scale. When the disc was made the positive pole, the effect was feeble.