Discharger, Universal.
An apparatus for exposing substances to the static discharge spark. It
consists of a base with three insulating posts. The central post carries
an ivory table to support the object. The two side posts carry
conducting rods, terminating in metal balls, and mounted with universal
joints. A violent shock can be given to any object placed on the table.
Synonym--Henley's Universal Discharger.
Discharge, Silent.
This term is sometimes applied to the glow or brush discharge and
sometimes to the condition of electric effluvium. (See Discharge,
Brush--Effluvium, Electric.)
Discharge, Spark.
The discontinuous discharge of high tension electricity through a
dielectric or into the air produces electric sparks. These are quite
strongly luminous, of branching sinuous shape, and in long sparks the
luminosity varies in different parts of the same spark. A sharp noise
accompanies each spark. High density of charge is requisite for the
formation of long sparks.
Disconnection.
The separation of two parts of, or opening a circuit, as by turning a
switch, unscrewing a binding screw, or the like. The term is sometimes
used to indicate a class of faults in telegraph circuits. Disconnections
may be total, partial or intermittent, and due to many causes, such as
open or partially replaced switches, oxidized or dirty contact points,
or loose joints.
Displacement, Electric.
A conception of the action of charging a dielectric. The charge is all
on the surface. This fact being granted, the theory of displacement
holds that charging a body is the displacing of electricity, forcing it
from the interior on to the surface, or vice versa, producing a positive
or negative charge by displacement of electricity. While displacement is
taking place in a dielectric there is assumed to be a movement or
current of electricity called a displacement current.
Disruptive Tension.
When the surface of a body is electrified, it tends to expand, all
portions of the surface repelling each other. The film of air
surrounding such a body is electrified too, and is subjected to a
disruptive tension, varying in intensity with the square of the density.
Dissimulated Electricity.
The electricity of a bound charge. (See Charge, Bound.)
Dissociation.
The separation of a chemical compound into its elements by a
sufficiently high degree of heat. All compounds are susceptible of
dissociation, so that it follows that combustion is impossible at high
temperatures.