IV. Experimental researches on the electric discharge with the chloride-of-silver battery.—Part I

In the Journal of the Chemical Society, November 1868, we first published an account of the “ Chloride-of-Silver Battery. Since 1874 we have commenced working with it systematically, and have gradually augmented the number of cells; we now possess 8040 in actual work, and have 2680 more completed, but not charged with fluid. Amongst the 8040 cells now in use are the first 1080 constructed in 1874, experiments with which we described on the 24th February, 1875. Subsequently from time to time we have communicated to the Society some of the results we have arrived at, and in the detailed communication of which the present is a short abstract we have given the full particulars of our experiments. The paper in question deals mainly with the strikingdistance between terminals of different forms in air and in other gases at ordinary atmospheric pressures, and in air at reduced pressures short of the partial vacua of the so-called vacuum tubes. Besides these experiments the paper describes the effects of currents of high tension in inducing secondary currents, and also their effects in inducing magnetism. We have found that the discharge of the battery, with one or two poles in the form of a point, presents several interesting phenomena which precede the true jump of the spark, and which do not occur with other forms of terminals—for example, disks or spherical surfaces. With 8040 cells the striking-distance between a paraboloidal point, positive, and a disk is about 0·34 in. (8·64 millims.); but there is always a luminous discharge, very apparent, far beyond the distance measurable by our micrometer-discharger, namely 1·16 inch (29·5 millims.), as we have before stated.