Conservation and Innovation : Helmholtz's Struggle with Energy ...

Weber have to be analysed "apart from that principle". That is, the requirement of
positive kinetic energy as a general rule is denied, but the possibility of specific
inadmissible conclusions from Weber’s law (which admits of negative kinetic
energy) is accepted. But as to this second problem C. Neumann also remarks that
Helmholtz’s criticism can be refuted: "The fact stressed by Helmholtz, i.e. the
occurrence of infinitely great accelerations, leads to either the conclusion that
Weber’s law is inadmissible, or that the singular states are not possible. And it
would therefore be overhasty to jump to the conclusion that one alternative is
preferable over the other and to take this fact to speak against Weber’s law" 401.
In fact, in his 1877 analysis, C. Neumann admits the second alternative and
refuses the first: "Indeed, this fact would only be evidence against Weber’s law if
one could prove, in an example, that those singular states are indeed possible. We
shall see later how far away we are from succeeding to find such proof." 402. But
twenty years later, in 1898, his position was different. He finally published the
second volume on "Electric forces". The first volume had been published in 1873
and was dedicated to an analysis of AmpÏere and F. Neumann’s theories.
Following the plan of the first volume the second should have dealt with Weber’s
and Kirchhoff’s theories. But instead the 1898 volume was dedicated to
Helmholtz’s theory. Neumann had finally accepted Helmholtz's theory.
It is well known that Helmholtz’s contributions to electrodynamics were also
relevant from the experimental point of view. In fact in the light of the
equivalence of theoretical predictions of the three theories for closed currents, he
stressed the importance of experimenting with open currents. This approach was
to lead to Hertz’s experiments of the late eighties, but still in the seventies
Helmholtz suggested three important experiments to Schiller (1874), Rowland
(1876) 403 and Hertz himself (1879). The first two experiments were interpreted in
favour of the dielectric theories (whether Helmholtz’s or Maxwell’s). Rowland in
particular demonstrated the electrodynamic effects caused by convection
currents. Hertz’s experiment was to deny the relevance of Weber’s electrical
inertia 404.
401 Ibidem p.324.
402 Ibidem p.324.
403 Woodruff "Helmholtz" pp.308-10.
404 Helmholtz n.394 p.6.