all the scientific men of the age, and, as deserved, set down as a man out of his senses. Nothing more was done for the next twenty-five years to enlarge the knowledge of the phenomena of electricity. It stood, in fact, on a footing not very far advanced from what it had been two thousand years before. The achievements mainly consisted in a great number of entertaining experiments performed for the delectation of great and little children. Various machines had been made for exciting electricity, but they served only, or at least chiefly, for amusement, allowing ladies to fire off a cannon by a touch of their delicate hand, and bringing ladies and gentlemen together to behold the wonderful spectacle of an infant’s hair being made to stand on end, the little creature having been placed upon cakes of resin, and fastened to the ceiling by silken cords. The whole was little more than a repetition, on a greater scale and with improved means, of the ancient Greek experiment of rubbing a piece of amber on the sleeve of a philosopher’s coat. The first great step towards a practical insight into the nature and phenomena of electricity, hitherto a mere plaything, was made in the year 1745 in the ancient Dutch city and university of Leyden. Two professors of the high school, John Nicholas Allamand, a member of the Royal Society of London, and Peter Van Musschenbroek, author of a treatise entitled ‘Introductio ad philosophiam naturalem,’ had been trying, like many other scientific men of the time, electrical experiments, when the thought occurred to them that the real reason why all the work of the same kind had as yet produced such slight results was that the electrical force was absolutely unstable. It slipped, so to speak, through their hands, before they could look at it; it vanished ‘like a dream, leaving no substance behind.’ One body, they knew, had the power of electrifying another, but only to let the mysterious force pass on, like a current of water running down a cataract. Could they but ‘bottle up’ electricity, what a grand gain would this be to science! So thought the two professors of Leyden university; and thought justly. They went on experimenting, with this end in view, till at last so-called ‘accident,’ the mother of millions of human inventions and discoveries, threw a brilliant light on the dark road along which they were groping their way.