In 1667, German alchemist Johann Joachim Becher identified this as the essence of fire. It was supposedly contained in all combustible substances.
The Greeks were convinced that diseases like malaria were spread by bad smells, dubbed miasmas. Medieval Europeans combated them with incense.
In the 1940s, psychoanalyst Wilhelm Reich posited that this substance composed of sexual energy can be collected for medicinal purposes. If only.
- Luminiferous ether
Descartes asserted that light and gravity traveled through this “more subtle than air” medium. Disproved by Einstein’s theory of relativity.
The 16th-century Swiss alchemist Paracelsus “discovered” this universal solvent. (Bonus misapprehension: The “philosopher’s stone” is made of alkahest.)