【医】 磁电

Electricity \E`lec*tric"i*ty\ ([=e]`l[e^]k*tr[i^]s"[i^]*t[y^]),
n.; pl. {Electricities} ([=e]`l[e^]k*tr[i^]s"[i^]*t[i^]z).
[Cf. F. ['e]lectricit['e]. See {Electric}.]
1. (Physics) a property of certain of the fundamental
particles of which matter is composed, called also
{electric charge}, and being of two types, designated
positive and negative; the property of electric charge on
a particle or physical body creates a force field which
affects other particles or bodies possessing electric
charge; positive charges create a repulsive force between
them, and negative charges also create a repulsive force.
A positively charged body and a negatively charged body
will create an attractive force between them. The unit of
electrical charge is the {coulomb}, and the intensity of
the force field at any point is measured in {volts}.
[PJC]

2. any of several phenomena associated with the accumulation
or movement of electrically charged particles within
material bodies, classified as {static electricity} and
{electric current}. Static electricity is often observed
in everyday life, when it causes certain materials to
cling together; when sufficient static charge is
accumulated, an electric current may pass through the air
between two charged bodies, and is observed as a visible
spark; when the spark passes from a human body to another
object it may be felt as a mild to strong painful
sensation. Electricity in the form of electric current is
put to many practical uses in electrical and electronic
devices. Lightning is also known to be a form of electric
current passing between clouds and the ground, or between
two clouds. Electric currents may produce heat, light,
concussion, and often chemical changes when passed between
objects or through any imperfectly conducting substance or
space. Accumulation of electrical charge or generation of
a voltage differnce between two parts of a complex object
may be caused by any of a variety of disturbances of
molecular equilibrium, whether from a chemical, physical,
or mechanical, cause. Electric current in metals and most
other solid coductors is carried by the movement of
electrons from one part of the metal to another. In ionic
solutions and in semiconductors, other types of movement
of charged particles may be responsible for the observed
electrical current.
[PJC]

Note: Electricity is manifested under following different
forms: (a)

{Statical electricity}, called also

{Frictional electricity} or {Common electricity}, electricity
in the condition of a stationary charge, in which the
disturbance is produced by friction, as of glass, amber,
etc., or by induction. (b)

{Dynamical electricity}, called also

{Voltaic electricity}, electricity in motion, or as a current
produced by chemical decomposition, as by means of a
voltaic battery, or by mechanical action, as by
dynamo-electric machines. (c)

{Thermoelectricity}, in which the disturbing cause is heat
(attended possibly with some chemical action). It is
developed by uniting two pieces of unlike metals in a bar,
and then heating the bar unequally. (d)

{Atmospheric electricity}, any condition of electrical
disturbance in the atmosphere or clouds, due to some or
all of the above mentioned causes. (e)

{Magnetic electricity}, electricity developed by the action
of magnets. (f)

{Positive electricity}, the electricity that appears at the
positive pole or anode of a battery, or that is produced
by friction of glass; -- called also {vitreous
electricity}. (g)

{Negative electricity}, the electricity that appears at the
negative pole or cathode, or is produced by the friction
of resinous substance; -- called also resinous
electricity. (h)

{Organic electricity}, that which is developed in organic
structures, either animal or vegetable, the phrase animal
electricity being much more common.

3. The science which studies the phenomena and laws of
electricity; electrical science.

4. Fig.: excitement, anticipation, or emotional tension,
usually caused by the occurrence or expectation of
something unusual or important.