A conducting wire leads from the pin into the waistcoat pocket, where a small “pile,” about the size of a cigarette, is hidden away. If any one particularly admires the scarf-pin, all you have to do is to insinuate your fingers into your pocket, and you will, by contact, cause the electric current to act upon the pin in your scarf. The death’s head will at once begin to roll its eyes and grind its teeth, while the rabbit, under similar circumstances, will begin to play its bell with the greatest energy. The handsome diamond bird represented in the centre of the illustration belongs to Madame de Metternich. When any lady wears it in her hair, she can, by the concealed wire, make it flap its jewelled wings, and by so doing cause much surprise amongst the spectators. We will now endeavour to give a description of the manner in which these toys play their parts in company with the “hermetic-pile” which M. Trouvé has applied to many specialities that he has supplied to doctors, who use them largely. This pile is formed by a “couple” of carbon and zinc hermetically enclosed in an ebonite box. The carbon and zinc only occupy one-half of the case. The liquid occupies the other. The sketch (fig. 280) on preceding page will explain the apparatus. So long as the case is in its normal position the elements are not immersed in the solution, and consequently no electricity is developed. But as soon as the figure is placed in a horizontal or leaning position the force is generated; on readjusting the box the electric current is cut off, and all development ceases. Many curious electrical toys can be seen in Paris. Dolls are made to talk, and many other wonders for children can be easily procured. ANIMAL AND ATMOSPHERIC ELECTRICITY. Before concluding the subject of electricity we must devote a few pages to the consideration of the electric influence possessed by certain fishes, and to some of the phenomena of the atmosphere, especially thunderstorms. We have seen how Galvani experimented upon the limbs of frogs, and maintained that they possessed electricity; he attributed the current in the muscles to that cause. This theory Volta denied, but subsequently Nobili, in 1827, proved the existence of a current in the frog by means of a Galvanometer. This was conclusive, and the experiment was performed in the following manner:—He filled two vessels with salt and water, and into one he dipped the crucal muscles of a frog, and in the other the lumbar nerves were immersed. By putting these vessels in communication with his improved Galvanometer, which was extremely sensitive, he perceived a current passing from the feet towards the head of the animal.