This is a list of substances or materials generally considered discredited.
A substance can be discredited in one of three ways:
#It was widely believed to exist at one time but no longer is. Such substances are often part of an
obsolete scientific theory
This list includes well-known general theories in science and pre-scientific natural philosophy and natural history that have since been superseded by other scientific theories. Many discarded explanations were once supported by a scientific co ...
.
#It was once believed to have drastically different properties from those accepted now. It was widely claimed and believed to possess significant properties that are no longer attributed to it.
#It is currently believed to exist as part of a theory that has not met the theoretical and experimental requirements of mainstream
science
Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...
. In particular, such a theory must be predictive.
Substances whose existence is discredited
Substances whose properties are discredited
This is not to be construed as implying that these items––are discredited. What is listed are fire, water, metal, etc. as universal principles or fundamentals.
*
Classical element
The classical elements typically refer to Earth (classical element), earth, Water (classical element), water, Air (classical element), air, Fire (classical element), fire, and (later) Aether (classical element), aether which were proposed to ...
s and
Chinese elements
( zh, c=五行, p=wǔxíng), usually translated as Five Phases or Five Agents, is a fivefold conceptual scheme used in many traditional Chinese fields of study to explain a wide array of phenomena, including terrestrial and celestial rela ...
discredited by
atomic theory
Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries. Initially, it referred to a hypothetical concept of ...
and
nuclear physics
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter.
Nuclear physics should not be confused with atomic physics, which studies th ...
.
**
Fire (classical element)
Fire is one of the four classical elements along with earth, water and air in ancient Greek philosophy and science. Fire is considered to be both hot and dry and, according to Plato, is associated with the tetrahedron.
Greek and Roman tradition ...
**
Water (classical element)
Water is one of the classical elements in ancient Greek philosophy along with air, earth and fire, in the Asian Indian system '' Panchamahabhuta'', and in the Chinese cosmological and physiological system '' Wu Xing''. In contemporary esoter ...
**
Earth (classical element)
Earth is one of the classical elements, in some systems being one of the four along with air, fire, and water.
European tradition
Earth is one of the four classical elements in ancient Greek philosophy and science. It was commonly associated ...
**
Air (classical element)
Air or Wind is one of the four classical elements along with water, earth and fire in ancient Greek philosophy and in Western alchemy.
Greek and Roman tradition
According to Plato, it is associated with the octahedron; air is considered to be ...
**
Wood (classical element)
In Chinese philosophy, wood (), sometimes translated as tree, is one of the five concepts that conform the ''wuxing''. It is the growing of the matter, or the matter's growing expanding stage. Wood is the lesser yang symbol of Yinyang characte ...
**
Metal (classical element)
In Chinese philosophy, metal or gold () is one of the five concepts that conform the ''wuxing''. It is the return or the declining stage, and is associated with the west, dusk, autumn, loss, grief, and the White Tiger. In Traditional Chinese Me ...
**
Aether (classical element)
According to ancient and History of science in the Middle Ages, medieval science, aether (, alternative spellings include ''æther'', ''aither'', and ''ether''), also known as the fifth element or quintessence, is the material that fills the regio ...
: Now known not to exist (see above)
* The
four bodily humours: Blood, Phlegm, Black Bile, and Yellow Bile. Fluids believed to determine health and character. Discredited by modern
biology
Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...
, including discovery of
hormones
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Hormones a ...
.
* The ''
tria prima
Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance.
H ...
'' of
Paracelsus
Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance.
H ...
and later
alchemy
Alchemy (from the Arabic word , ) is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was historically practised in China, India, the Muslim world, and Europe. In its Western form, alchemy is first ...
: Salt, Mercury and Sulphur. Discredited by modern
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
(the
atomic theory
Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries. Initially, it referred to a hypothetical concept of ...
and modern understanding of elements and compounds).
See also
*
*
List of misidentified chemical elements
References
{{DEFAULTSORT:Discredited substances
Obsolete scientific theories
Chemistry-related lists
Pseudoscience