"I was so fortunate (says Professor Owen) as to witness the experiments performed by Professor Faraday on the large gymnotus which was so long preserved at the Adelaide Gallery, in London. That the most powerful shocks were received when the one hand grasped the head, and the other hand the tail of the gymnotus, I had painful experience, especially at the wrists, the elbow, and across the back. But our distinguished experimenter showed us that the nearer the hands were together, within certain limits, the less powerful was the shock. He demonstrated by the galvanometer that the direction of the electric current was always from the anterior parts of the animal to the posterior parts, and that the person touching the fish with both hands received only the discharge of the parts of the organs included between the points of contact. Needles were converted into magnets; iodine was obtained by polar decomposition of iodide of potassium; and availing himself of this test, Professor Faraday showed that any given part of the organ is negative to other parts before it, and positive to such as are behind it. Finally, heat was evolved, and the electric spark obtained." ------------------ TALENT AND OPPORTUNITY. Previous to the year 1706, the brass ordnance for the British Government was cast at the foundry in Moorfields; but an accident which occurred there at the above date, led to the removal of the foundry to Woolwich. The circumstances connected with this change are interesting, as well as instructive. It appears that a great number of persons had assembled to witness the re-casting of the cannon taken by the Duke of Marlborough from the French; and there happened to be among them, a young German artisan in metal, named Schalch. Observing some moisture in the moulds, he pointed out to the spectators around him the danger likely to ensue from an explosion of steam, when the moulds were filled with the heated metal; and at the instigation of his friends, this apprehension was conveyed through Colonel Armstrong, major-general of the Ordnance, to the Duke of Richmond, then in attendance, as the head of the department. This warning was, however, disregarded; but Schalch retired from the spot with as many of the bystanders as he could persuade to accompany him. They had not proceeded far before the furnaces were opened, and, as Schalch had foretold, a dreadful explosion ensued. The water in the moulds was converted into steam, which from its expansive force caused a fiery stream of liquid metal to dart out in every direction. Part of the roof of the building was blown off, and the galleries that had been erected for the company were swept to the ground. Most of the foundrymen were terribly burnt; some were killed; and many of the spectators were severely injured.