General Physiology, Cellular Physiology, the Energetics of Living Beings.—General physiology, as was taught by Pflüger and his school, claims to go deeper down than the apparatus, or the organ, or even the cell. As in the case of physics, general physiology endeavours to reach, and really does in many cases reach, as far as the molecule. It is not cellular, it is molecular. Already, in fact, the efforts of modern science have succeeded in penetrating into the most general phenomena of the living being—those attributable to living matter, or, to speak more clearly, those which result from the play of the universal laws of matter at work in this particular medium which is the organized being.
Robert Mayer and Helmholtz have the honour of having set physiology in the right road. They founded the energetics of living beings—i.e., they regarded the phenomena of life from the point of view of energy, which is the factor of all the phenomena of the universe.
