Hermann von Helmholtz, with several other associates in the sciences, particularly Emil duBois-Reymond and Karl Ludwig, forms the so-called 1847, or mechanistic, school of physiology, which attempts to explain physiological phenomena in terms of chemistry and physics.

Helmholtz completes a series of papers published between 1843 and 1847 in which he applies these principles to animal heat and muscle contraction, then outlines the physical and philosophical basis of the law of the conservation of energy (a hot topic at this time) “On the Conservation of Energy.”