The German chemist Baron Carl von Reichenbach (1788–1869) claimed in the mid-19th century to have discovered a previously unknown fundamental force in nature, which he called “od” after the Germanic god Odin. Also referred to as “odyle” or “odic force”, it was said to be pervasive, yet no machine could detect it, only those individuals whom Reichenbach called “sensitives”.
Reichenbach had been investigating the effects of various substances on the human nervous system when he conceived the idea of a new force, allied to electricity, magnetism, and heat, which he thought was radiated by most substances, and to which individuals are differentially sensitive.
Believers in Odic force said that it was visible in total darkness as coloured auras surrounding living things, crystals and magnets, but that viewing it required hours first spent in total darkness, and very sensitive people observers. It was said by some to be analogous to Asian concepts such prana and qi, but differed in its association mainly with biological electrical fields rather than breath.
Reichenbach’s aim of proving the existence of a universal life force was hampered by his own inability to observe the phenomenon he was reporting, forcing him to rely on the accounts of those who claimed to be sensitive. Given the consequent lack of reliable or replicable data, the idea of odic force was considered by many contemporary scientists to be quackery, and is today regarded as an example of pseudoscience.