base our conviction that even the _atom_ is not without a rudimentary form of sensation and will, or as it is better expressed, of feeling (_aesthesis_) and inclination (_tropesis_)--that is, a universal "soul" of the simplest character. The same must be said of the molecules which are composed of two or more atoms. Further combinations of different kinds of these molecules give rise to simple and, subsequently, complex chemical compounds, in the activity of which the same phenomena are repeated in a more complicated form. The study of ether, or imponderable matter, pertains principally to physics. The existence of an extremely attenuated medium, filling the whole of space outside of ponderable matter, was known and applied to the elucidation of various phenomena (especially light) a long time ago; but it was not until the second half of the nineteenth century that we became more closely acquainted with this remarkable substance, in connection with our astonishing empirical discoveries in the province of electricity, with their experimental detection, their theoretical interpretation, and their practical application. The path was opened in particular by the famous researches of Heinrich Hertz, of Bonn, in 1888. The premature death of a brilliant young physicist of so much promise cannot be sufficiently deplored. Like the premature death of Spinoza, Raphael, Schubert, and many other great men, it is one of those brutal facts of human history which are enough of themselves to destroy the untenable myth of a "wise Providence" and an "All-loving Father in heaven."