The conversion of two or more chemicals into a new compound or substance.
Deflection. In magnetism, the movement of the needle out of the plane. It is due to disturbance, or to the needle’s attraction towards a mass of iron or steel or another magnet.
Demagnetization. The removal of magnetism from a paramagnetic substance. The process is principally in use for watches which have become magnetized by exposure to the magnetic field surrounding dynamos or motors.
Density, Electric. The relative quantity of electricity, as a charge, upon a unit area of surface. It may be positive or negative.
Surface density, as the charge of a Leyden-jar.
Depolarization. A term applied to the removal of permanent magnetism, such as that from a horseshoe magnet, a watch, or a bar-magnet. Heat is the common depolarizer, but counter electro-magnetic forces are employed also in the various forms of apparatus known as demagnetizers.
Deposit, Electrolytic. The metal or other substances precipitated by the action of a battery or other current-generator, as in the plating processes.
Detector. A portable galvanometer, by means of which a current and its approximate strength can be detected and measured.
Diaphragm. In telephones and microphones, a disk of iron thrown into motion by sound-waves or by electric impulse. It is usually a thin plate of japanned iron, such as is used in the ferrotype photographic process for making tin-types.
Dielectric. Any substance through which electrostatic induction is allowed to occur, such as glass or rubber. It is a non-conductor for all electric currents.