A toxin (from Ancient Greek: τοξικόν  "toxikon" ) is a poisonous substance produced within living cells or organisms; synthetic toxicants created by artificial processes are thus excluded.
 The term was first used by organic chemist Ludwig Brieger (1849–1919).
In chemistry a Zintl phase is the product of a reaction between a group 1 (alkali metal) or group 2 (alkaline earth) and any post transition metal or metalloid (i.e. from group 13, 14, 15 or 16).
 It is named after the German chemist Eduard Zintl who investigated them in the 1930s, with the term "Zintl Phases" first used by Laves in 1941.
Klausism is a term used to describe the political positions of Václav Klaus, former Prime Minister and President of the Czech Republic.
 It was first used by Mirek Topolánek, who considers Klausism the official ideology of the Civic Democratic Party.
 This term was also used by Jan Kasl.
 Klaus does not take issue with the term.
 The current usage of the term Klausism is distant from its origin, which engendered the phrase "Klausism without Klaus".
 Though Klausism primarily refers to the political ideology, it is frequently used as a label for the neologisms invented by Klaus.
Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity, and other resources.
 The term "anthropogenic" designates an effect or object resulting from human activity.
 The term was first used in the technical sense by Russian geologist Alexey Pavlov, and was first used in English by British ecologist Arthur Tansley in reference to human influences on climax plant communities.
 The atmospheric scientist Paul Crutzen introduced the term "Anthropocene" in the mid-1970s.
 The term is sometimes used in the context of pollution emissions that are produced as a result of human activities but applies broadly to all major human impacts on the environment.
Hard science fiction is a category of science fiction characterized by an emphasis on scientific accuracy.
 The term was first used in print in 1957 by P. Schuyler Miller in a review of John W. Campbell's "Islands of Space" in "Astounding Science Fiction".
 The complementary term soft science fiction, formed by analogy to hard science fiction, first appeared in the late 1970s.
 The term is formed by analogy to the popular distinction between the "hard" (natural) and "soft" (social) sciences.
 Science fiction critic Gary Westfahl argues that neither term is part of a rigorous taxonomy; instead they are approximate ways of characterizing stories that reviewers and commentators have found useful.
Irving Langmuir (January 31, 1881 – August 16, 1957) was an American chemist and physicist.
 His most noted publication was the famous 1919 article "The Arrangement of Electrons in Atoms and Molecules" in which, building on Gilbert N. Lewis's cubical atom theory and Walther Kossel's chemical bonding theory, he outlined his "concentric theory of atomic structure".
 Langmuir became embroiled in a priority dispute with Lewis over this work; Langmuir's presentation skills were largely responsible for the popularization of the theory, although the credit for the theory itself belongs mostly to Lewis.
 While at General Electric from 1909 to 1950, Langmuir advanced several basic fields of physics and chemistry, invented the gas-filled incandescent lamp and the hydrogen welding technique, and was awarded the 1932 Nobel Prize in Chemistry for his work in surface chemistry.
 The Langmuir Laboratory for Atmospheric Research near Socorro, New Mexico, was named in his honor, as was the American Chemical Society journal for surface science called "Langmuir".
Measured Lies: The Bell Curve Examined is a notable collection of essays on pathological science and pseudoscientific methods used in the science of sociology, both widely praised and derided by academicians reviewing it.
 The essays respond to arguments in the book "The Bell Curve".
 The essays introduce the expression “hoodoo science” as a synonym for “pseudoscience” in sociology.
 Michael Eric Dyson, author, radio host, National Public Radio, CNN, and "Real Time with Bill Maher" commentator, and professor of sociology at Georgetown University, called it "the most thorough and cogent analysis of the tangle of pseudo-science and moral dishonesty that comprises the frozen heart of "The Bell Curve"."
The fantasy of manners is a subgenre of fantasy literature that also partakes of the nature of a comedy of manners (though it is not necessarily humorous).
 Such works generally take place in an urban setting and within the confines of a fairly elaborate, and almost always hierarchical, social structure.
 The term was first used in print by science fiction critic Donald G. Keller in an article, "The Manner of Fantasy", in the April, 1991 issue of "The New York Review of Science Fiction", although author Ellen Kushner has said that she suggested the term to Keller.
 The subgenre, or a close relative to it, has also been called mannerpunk, a tongue-in-cheek reference to the cyberpunk subgenre of science fiction.
Pathological science is an area of research where "people are tricked into false results ... by subjective effects, wishful thinking or threshold interactions."
 The term was first used by Irving Langmuir, Nobel Prize-winning chemist, during a 1953 colloquium at the Knolls Research Laboratory.
 Langmuir said a pathological science is an area of research that simply will not "go away"—long after it was given up on as "false" by the majority of scientists in the field.
 He called pathological science "the science of things that aren't so".
Ars nova (Latin for new art) refers to a musical style which flourished in France and the Burgundian Low Countries in the Late Middle Ages: more particularly, in the period between the preparation of the "Roman de Fauvel" (1310s) and the death of the composer Guillaume de Machaut in 1377.
 The term is sometimes used more generally to refer to all European polyphonic music of the 14th century.
 For instance, "Italian ars nova" is sometimes used to denote the music of Francesco Landini and his compatriots (although Trecento music is the more common term for music in Italy).
 The "ars" in "ars nova" can be read as "technique", or "style".
 The term was first used in two musical treatises, titled "Ars novae musicae" (New Technique of Music) (c. 1320) by Johannes de Muris, and a collection of writings (c. 1322) attributed to Philippe de Vitry often simply called "Ars nova" today.
 However, the term was only first used to describe an historical era by Johannes Wolf in 1904.

Question: When was the chemist who first used the term Pathological science born?
Answer: January 31, 1881