Hence it must be concluded that the electro-motive force of the parelectronomic layer remains constant in the act of contraction. 13. If any part of a nerve is submitted to the action of a permanent current, the nerve in its whole extent suddenly undergoes a material change in its internal constitution, which disappears on breaking the circuit as suddenly as it came on. 14. The electrical phenomena of motor and sensitive nerves are identical. Both classes of nerves transmit irritation in both directions. We will merely say in addition to these laws, that, in examining who was right between Galvani and Volta, we find that they were both in some points right, and in some others wrong. Galvani was right in saying that there is an animal electricity, and Volta was right in looking at the heterosreneitv of metals as a source of electricity; and had he extended his views to the living tissues, he would have found that there also, as in metals, where there are two heterogenic particles in contact one with the other, a galvanic current is generated.

II. The production of static electricity in animals. A constant production of this kind of electricity cannot be doubted; but animals and men being in free communication with the earth, it is rarely possible to ascertain the presence of this electricity. But when the body of a man is insulated he may affect the electrometer. If two men are insulated, as it often occurs that they are charged with different electricities, there is when they touch each other a peculiar crackling, and sometimes a spark, announcing the combination of the vitreous and the resinous electricity. In dry weather many persons may hear the sound and see the light resulting from a combination, when they suddenly pull off the articles of dress in contact with their skin. Dr. Schneider mentions a Capuchin friar who, on removing hi3 cowl, used to perceive a number of shining, crackling sparks passing from his scalp. But it is in the United States that the most interesting fact concerning the production of static electricity has been observed.

It was in a lady, who for many months was in an electrical state so different from that of surrounding bodies, that, whenever she was but slightly insulated by a carpet or other non-conducting medium, sparks would pass between her person and any object she approached; when she was most favorably circumstanced, four sparks per minute would pass from her linger to the brass ball of the stove at the distance of 1 1/2 inch. Sometimes the electricity thus developed is sufficient to light the gas from an ordinary burner. From the pain which accompanied the passage of the sparks, the lady's condition was a source of much discomfort to her. The circumstances which appeared most favorable to the production of electricity were an atmosphere of 80° F., tranquillity of mind, and social enjoyment; while alow temperature and depressing emotions diminished it in a corresponding degree. The phenomenon was first noticed during the occurrence of an aurora borealis; and though its appearance was sudden, its departure was gradual.

Articles of dress had no influence upon its intensity.