The action produced in nerve or muscle of the animal system by an alternating or intermitting high potential discharge from an induction coil.

The office to which telephone wires lead in a general telephone system. In the office by a multiple switch board, or other means, the different telephones are interconnected by the office attendants, so that any customers who desire it may be put into communication with each other. The exchange is often termed the Central Office, [...]

The superficial sublimation or evaporation of a substance under the influence of negative electricity. It is one of the effects investigated by Crookes in his experiments with high vacua. He found that when a metal, even so infusible as platinum, was exposed to negative electrification in one of his high vacuum tubes, that it was [...]

A graduated glass tube for measuring the volumes of gases. In its simplest form it is simply a cylindrical tube, with a scale etched or engraved upon it, closed at one end and open at the other. The gas to be measured is collected in it over a liquid, generally water, dilute sulphuric acid in [...]

The ether is a hypothetical thing that was invented to explain the phenomena of light. Light is theoretically due to transverse vibrations of the ether. Since the days of Young the conception of the ether has extended, and now light, “radiant heat,” and electricity are all treated as phenomena of the ether. Electrical attraction and [...]

A process of producing an etched plate. The plate is coated with wax, and the design traced through as in common etching. It is then placed in a bath and is connected to the positive terminal from a generator, whose negative is immersed in the same bath, so that the metal is dissolved by electrolytic [...]

A term applied to leakage of current.

Ten millions of ergs, or ten meg-ergs.

The absolute or fundamental C. G. S. unit of work or energy. The work done or energy expended in moving a body through one centimeter against a resistance of one dyne.

“The mechanical energy of one volt electro-motive force exerted under unit conditions through one equivalent of chemical action in grains.” (J. T. Sprague.) This unit is not in general use as the unit of electric energy, the volt-coulomb and (for rate of electric energy) the volt-ampere being always used.