List of discredited substances

This page is a list of substances or materials which are generally considered to be discredited.

A substance may be discredited in one of three ways:

1. It was widely believed to exist at one time but is not any more. Such substances are often part of an obsolete scientific theory.
2. It was once believed to have drastically different properties from those accepted now. Significant properties it was widely claimed and believed to possess are no longer accepted.
3. It is currently believed to exist as part of a theory which has not met the theoretical and experimental requirements of mainstream science. In particular, such a theory must be predictive.

Alphabetical list of substances whose existence is discredited

• Alicorn - The horn of the unicorn which was believed to have mystical healing properties. Discredited by failure to find any since medieval times.
• Alkahest - The hypothetical universal solvent, having the power to dissolve every other substance, including gold. Note that aqua regia can dissolve gold, but not everything.
• Caloric - Weightless fluid believed to be the substance of heat. Discredited by atomic theory, in which heat is interpreted as energy of motion of atoms.
• Carmot - Substance believed by alchemists to be a component of the Philosophers' Stone (see below).
• Coronium - Chemical element hypothesized to exist in the solar corona. Discredited by enumeration of elements in the periodic table.
• Élan vital - Substance or force believed to bear the property of life. Discredited by molecular biology.
• Elixir of life - Substance believed by alchemists to confer immortality. Discredited by chemistry and biology.
• The Erototoxins of Judith Reisman - Addictive chemicals allegedly produced in the brain by pornography. There are addictive opioids (i.e. endorphins) in the brain related to pleasure in general, but not specific to pornography.
• Luminiferous aether - Medium for the propagation of light. Discredited by Michelson-Morley experiment.
• Miasma - Foul smell believed to carry diseases. Discredited by modern biology, in particular the discovery of actual infectious agents.
• The N-rays of Prosper-René Blondlot - A form of radiation believed to be emitted by most substances. Discredited by a simple null experiment, in which Blondlot thought he could see N-rays even when an essential optical element had been removed from the experiment.
• The Odic force of Carl Reichenbach - Force believed to bear the property of life. Never accepted by science, due to a lack of experimental evidence and any predictive theory.
• The orgone energy of Wilhelm Reich - Energy believed to bear the property of life. Never accepted by science, due to a lack of experimental evidence and any predictive theory.
• Panacea - Substance believed by Alchemists to cure all illness. Discredited by biology and medicine.
• Philosopher's stone - Substance believed by Alchemists to transmute other metals into gold. Discredited by atomic theory.
• Phlogiston - Weightless substance believed to be the present in combustible materials and released when they are burned. Discredited by modern chemistry, specifically the discovery that combustion is combination of various substances with oxygen.
• Polywater - An apparently polymerised form of water. Discredited by more careful experiments with rigorously cleaned glassware.
• Ptomaines - alkaloids found in decaying matter thought to cause food poisoning. Discredited by discovery of bacteria.
• Red mercury - Controversial substance alleged to be of use to terrorists. Its actual nature, if any, is unclear.
• The Terra Pinguis (combustible earth) of J. J. Becher - The forerunner of phlogiston.^{[citation needed]} Discredited to some extent because it would have had negative weight, and finally by Lavoisier's invention of the beginnings of modern quantitative chemistry. It turns out that Terra Pinguis is equivalent to the absence of oxygen.

Alphabetical list of substances whose properties are discredited

This is not to be construed as implying that these items–as they are understood today–are discredited. What is listed are fire, water, metal, etc. as universal principles or fundamentals.

• Classical elements and Chinese elements Discredited by atomic theory and nuclear physics.
  • Fire (classical element)
  • Water (classical element)
  • Earth (classical element)
  • Air (classical element)
  • Wood (classical element)
  • Metal (classical element)
  • Aether (classical element)
• The four bodily humours: Blood, Phlegm, Black Bile, & Yellow Bile. Fluids believed to determine health and character. Discredited by modern biology, including discovery of hormones.
• The tria prima of Paracelsus and later alchemy: Salt, Mercury and Sulphur. Discredited by modern chemistry (the atomic theory and modern understanding of elements and compounds).

See also

• List of fictional toxins
• List of fictional elements, materials, isotopes and atomic particles

Notes