"It is well known that matter consists of small particles, the atoms, and that the macroscopic phenomena are but manifestations of combinations and interactions among these atoms. But physics did not stop there: at the end of that last century it discovered atomic electricity of a still stranger behavior. Although up to then it had been held that electricity was a fluid and acted as a kind of continuous eye, it became clear then that electricity too, is built up of positive and negative electrons. Now besides matter and electricity there exists in physics another reality, for which the law of conservation holds; namely energy. But even energy, it is found, does not admit of simple and unlimited divisibility. Planck discovered the energy-quanta. And the verdict is that nowhere in reality does there exist a homogeneous continuum in which unlimited divisibility is possible, in which the infinitely small can be realized. The infinite divisibility of a continuum is an operation which exists in thought only, is just an idea which is refuted by our observations of nature, as well as by physical and chemical experiments."