Doctor Watson and many other gentlemen of eminence in science, were at the pains of making experiments of the same kind. They found, by means of a wire insulated on baked wood, that the electric shock was transmitted instantaneously through the length of 12,276 feet. Electricity transmitted in large quantities through living vegetables, destroys their vegetable life. When transmitted, in the same form, through animals, it generally puts an end to animal life; though it is said that there are individuals who are not affected by it. Possibly the reason why some persons are not killed by very large electric shocks is, that their muscular system, or bodily organization, has something peculiar which protects them. If an electrical circuit be made by means of imperfect conductors, as a slender piece of wood, a wet pack-thread, the discharge will be made silently. If a small interruption of an electrical circuit be made in water, on making the discharge, a spark will be seen in the water, which never fails to agitate it and sometimes breaks the vessel in which it is contained. A strong shock from a battery, sent through a slender piece of metal, instantly makes it red hot. Usually it is melted in whole or in part. If the fusion be perfect it is reduced into globules of different magnitudes. In this experiment it is a little remarkable that the parts of the metal at which the fluid enters and issues, are most likely to be melted. If the metal be enclosed between pieces of glass, the shock will force the melted metal into the substance of the glass, so that it cannot afterwards be removed, without scraping off part of the glass with it. In this experiment the glasses which enclose metal are commonly broken to pieces.—It is seldom that they resist the force of a strong shock. If the glasses enclosing metal be pressed by a heavy weight, a small shock is often sufficient not only to raise the weight, but to break glasses of considerable thickness. When the pieces of glass are not broken, they are marked by the explosion with the most lively prismatic colours, which lie sometimes irregularly, and sometimes in their prismatic order. Gun-powder may be fired by a charge from three square feet of coated glass. The powder is to be put into a quill, and then a wire is to be thrust into each end so as nearly to meet, and afterwards these wires are to be made a part of an electrical circuit.—A less charge of electricity will be sufficient if iron filings be mixed with the gun-powder.