Home | Up One Level | Previous | Next
Table of Contents | Previous Section | Next Section
§8. – CONVECTIVE ACTION OF ELECTRICITY. –
EXPERIMENTS
OF ROWLAND, RÖNTGEN AND EICHENWALD
WALTER RITZ
Translated from Recherches
critiques sur l'Ėlectrodynamique Générale,
Annales de Chimie et de Physique, Vol. 13,
p. 145, 1908.
Annales 240
(Oeuvres 396)
Lastly let us consider an electrostatic charge
swept along with a speed V' by the body which carries it and acting on a
magnetized needle, that is to say on a system of closed and neutral currents,
of nil electrostatic charge, whose positive ions are motionless, the negative
ions having the speed v. An element ds of one of these currents
will be subject to a force dRx, dRy, dRz, which
is the sum of the actions of 
on its positive charge E'ds and its
negative charge –E1ds, and expression (13) will give
The ensemble of terms proportional to V' and v have the form already obtained several
times; we have besides
(Oeuvres 397) which we can integrate in relation to ds (this
current being closed), as previously done in relation to ds', and we
find again the formula which would be deduced from Lorentz’s theory. A
transformation of this type will always be
possible as soon as at least one of the currents is
closed. The additive terms in 
would give a
resultant force and no couple for the magnet, a force whose intensity, always
very small, which depends on the hypotheses made on the movement of the ions in
the magnet and is negligible in relation to the couple if v is small
in relation to V, whether the negative electricity by itself is mobile or
not.
When a dielectric is polarized by electrostatic forces there results in
its surface identical electric charges according to both theories. If the
electrostatic field varies, or if the dielectric is mobile, the movement of
these charges will still be the same from both points of view and, we have just
seen that these mobile charges will have the same action on a magnet. In the
theories of Hertz and Lorentz, another action is added to this action, that of
the displacement current relative to the ether which is proportional to the
speed of the change of the electric force in one point of the ether. As in
Röntgen’s experiment[1],
the same as in those of Eichenwald[2],
this action is nil in Lorentz’s theory, which consequently will give the same
results, consistent with the experiment, as our formula.
To obtain an action dependent on k, that is to say an experimentum
crucis, one has to be able to observe electrodynamic or electromagnetic
forces between both non-closed or non-neutral currents. This has not yet been
achieved.
[1] Annalen der Physik u. Chemie, t.
XXXV, 1888, p. 264.
[2] Ann. der Physik, 4 série, t. XI, 1903, p. 1 et 421.
Table of Contents | Previous Section | Next Section