logical form, the electromagnetically founded mechanics of course cannot compare itself to Hertz's one, just because the system of Maxwell's differential equations has found no precise-critical treatment at all, but it has, as it seems to me, a very remarkable advantage, namely (as it was shown) that it transcends ordinary mechanics, which therefore is only to be described as a first approximation. By that, the possibility is given, to decide for or against it by experience.
(Received May 19, 1901.)
