Factitious airs was a term used for synthetic gases which emerged around 1670 when

Robert Boyle Robert Boyle (; 25 January 1627 – 31 December 1691) was an Anglo-Irish natural philosopher, chemist, physicist, Alchemy, alchemist and inventor. Boyle is largely regarded today as the first modern chemist, and therefore one of the foun ...

coined the term upon isolating what is now understood to be

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

. ''Factitious'' means "artificial, not natural", so the term means "man-made gases".

Background

coined the term Factitious Air upon isolating

in 1670.

Henry Cavendish Henry Cavendish ( ; 10 October 1731 – 24 February 1810) was an English experimental and theoretical chemist and physicist. He is noted for his discovery of hydrogen, which he termed "inflammable air". He described the density of inflammable a ...

(1731–1810) used the term "factitious air" to refer to "any kind of air which is contained in other bodies in an unelastic state, and is produced from thence by art". An archaic definition from 1747 for the production of factitious air was defined as being caused by: "1- by flow Degrees from Putrefactions and Fermentations of all Kinds; or 2- more expeditiously by some Sorts of chymical Dissolutions of Bodies; or 3- and lastly, almost instantaneously by the Explosion of Gunpowder, and the Mixture or some Kinds of Bodies. Thus, if Paste or Dough with Leaven be placed in an exhausted Receiver, it will, after some Time, by Fermentation, produce a considerable quantity of Air, which will appear very plainly by the Sinking the Quicksilver in the Gage. Thus also any Animal or Vegetable Substance, putrifying ''in Vacuo'', will produce the same Effect." There are significant inconsistencies in the archaic nomenclature due to the limited knowledge of chemistry and primitive analytical technology of the era (i.e. based on the chemistry, it is clear the terms were mistakenly assigned to more than one gas by different investigators). Furthermore, in most cases the gases were not pure.

Factitious Airs

Names used for factitious airs may have included:

Ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

* ammonical gas *ammoniac *volatile alkali *alkaline air *gaseous ammonia *azoturetted hydrogen

Carbon Dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

Fixed Air

Source: Fixed air, or fixible air, is an ancient term for carbon dioxide

Joseph Priestley Joseph Priestley (; 24 March 1733 – 6 February 1804) was an English chemist, Unitarian, Natural philosophy, natural philosopher, English Separatist, separatist theologian, Linguist, grammarian, multi-subject educator and Classical libera ...

credited

Joseph Black Joseph Black (16 April 1728 – 6 December 1799) was a British physicist and chemist, known for his discoveries of magnesium, latent heat, specific heat, and carbon dioxide. He was Professor of Anatomy and Chemistry at the University of Glasgow ...

for discovering and coining "fixed air", which was thought to exist in a fixed state in alkaline salts, chalk, and other calcareous substances. Black considered substances containing fixed air to be "mild", and upon expulsion of the gas by heating the resulting state is "caustic" by corroding or burning plants and animals (e.g. released by chalk upon decomposition to calcium oxide). In other words, the fixed air (also known as fixible air) was thought to be fixated within a corrosive molecule. Priestley likewise credited the discovery of fixed air to contributions from several scientists including: David Macbride, John Pringle,

William Brownrigg William Brownrigg ( – 6 January 1800) was an English physician and scientist who practised at Whitehaven in Cumberland. While there, Brownrigg carried out experiments that earned him the Copley Medal in 1766 for his work on carbonic acid gas. H ...

(regarded carbonated water to have an acidulous taste),

Stephen Hales Stephen Hales (17 September 16774 January 1761) was an English clergyman who made major contributions to a range of scientific fields including botany, pneumatic chemistry and physiology. He was the first person to measure blood pressure. He al ...

, and many others.

provided a definition: "By fixed air, I mean that particular species of factitious air, which is separated from alkaline substances by solution in acids or by

calcination Calcination is thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), generally f ...

". Cavendish essentially defined potassium oxide or calcium oxide as a base, which can contain a fixated air within its composition, setting the stage for the historical definition of carbonate.

Carbonic Acid

Source: According to

Claude Louis Berthollet Claude Louis Berthollet (, 9 December 1748 – 6 November 1822) was a Savoyard-French chemist who became vice president of the French Senate in 1804. He is known for his scientific contributions to the theory of chemical equilibria via the ...

, "What has long been called ''fixed'', or ''fixible air'', being really an acid in the state of gas, has of late received several new denominations. It has been called ''aerial acid'', as existing very readily in the state of air, or more properly of gas, and plentifully in the atmosphere. The ''chalky acid'', as procurable in large quantities from chalk, or other mild calcareous substances. The name given to it in this essay is derived from the knowledge of its composition, as lately ascertained by the French Chemists to consist of the elementary part of charcoal, named ''charbone'', or ''char'', united with ''oxygen'', or the acidifying principle. Hence it is called, with strict propriety, ''carbonic acid'' in general; ''carbonic acid gas'' when in the aerial form; and ''carbonic acid liquor'' when combined with or dissolved in water." By French Chemists, Berthollet is generally referring to

Lavoisier Antoine-Laurent de Lavoisier ( ; ; 26 August 17438 May 1794),
CNRS (

The name

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

is derived from Greek with oxy meaning acid, and gene to mean forming/expression, therefore carbonic acid is simply the union of carbon with oxygen (Laviosier's original degrees of oxidation could not fit the concept of carbon monoxide as it was based on diamond, graphite, coal and carbonic acid)

Carbonate

Carbonate was defined as "a compound formed by the union of carbonic acid with an earth, alkali, or metallic oxide ..they are distinguished by the property of effervescing on the addition of an acid" The definition expands upon fixed air being fixated within carbonate to suggest carbonic acid is a constituent of carbonate, therefore in the ancient language the suffix "-ic acid" and "-ate" were not interchangeable. The modern definition is similar, although equipped with the molecular knowledge of carbonate's structure and reassignment of the meaning of carbonic acid from CO₂ to the H₂CO₃ molecule, "Carbonates are the salts of carbonic acids. They form when a positively charged metal ion comes into contact with the oxygen atoms of the carbonate ion."

Bicarbonate

Bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial bioche ...

, originally known as bi-carbonate of potash, was coined by

William Hyde Wollaston William Hyde Wollaston (; 6 August 1766 – 22 December 1828) was an English chemist and physicist who is famous for discovering the chemical elements palladium and rhodium. He also developed a way to process platinum ore into malleable i ...

in 1814 based on hydrocarbonate's potential to release two molar equivalents of carbon dioxide (referred to as carbonic acid at the time) as released by both potassium hydrocarbonate (initially known as carbonate of potash, suggested to become bicarbonate) and potassium carbonate (vaguely known as subcarbonate, suggested to become carbonate) upon formation of potash (potassium oxide). Bicarbonates have historically been defined as, "combinations of the bases with the carbonic acid, in which two atoms of the latter are united to one of the former" In other words, potash (potassium oxide) was well-understood to be a caustic base and essentially the core molecule that subsequent chemical nomenclature was built upon. Carbonate of potash (potassium carbonate) must contain a carbonic acid species fixated within potash's alternative composition (see fixed air above). Since "bi-carbonate of potash" liberates a double dose of carbonic acid, to distinguish between the similar substances, the prefix bi- indicates the bi-carbonate of potash (potassium hydrocarbonate) contains twice as much fixated in this form potash's composition relative to the carbonate of potash. The same ancient logic (prior to the understanding of molecular formulas and reaction stoichiometry) applied to soda, carbonate of soda, and bicarbonate of soda. The word ''saleratus'', from

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''sal æratus'' (meaning "aerated salt"), was widely used beginning in the 1840s.

Carbonic acid gas

Carbonic acid gas was an ancient term to specify the gaseous state of carbonic acid (synonymous with carbonic acid). It is listed as an alternative name for carbon dioxide in PubChem. In 1796 externally applied carbonic acid gas to the epidermis was reported to treat breast cancer; and inhalation treated tuberculosis and other indications.

Miscellaneous historical names

* gas silvestre **Ancient origin for fixed air by

Jan Baptist van Helmont Jan Baptist van Helmont ( , ; 12 January 1580 – 30 December 1644) was a chemist, physiologist, and physician from Brussels. He worked during the years just after Paracelsus and the rise of iatrochemistry, and is sometimes considered to be ...

*Spiritus sylvestris *aerial acid *acid of air *luft-saeure *carbonic anhydride *Gas acide carbonique *Gas carbonicum *chalky acid *acid of chalk *kriedesaeure *kohlensaeures gas *choke-damp *cretaceous acid *Acide mephitique *Mephitic air *deutoxide of carbon

Carbon monoxide Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

* hydrocarbonate **

Water gas Water gas is a kind of fuel gas, a mixture of carbon monoxide and hydrogen. It is produced by "alternately hot blowing a fuel layer okewith air and gasifying it with steam". The caloric yield of the fuel produced by this method is about 10% o ...

prepared by passing steam over charcoal/ coke. Alternatively prepared from unspecified alcohol and sulphuric acid. **Hydrocarbonate was recognized to brighten venous blood and compete with oxygen around 1796, although credit is widely awarded to

Claude Bernard Claude Bernard (; 12 July 1813 – 10 February 1878) was a French physiologist. I. Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science". He originated the term ''milieu intérieur'' and the associated c ...

's work in the mid-1850s. *hydrocarbonous acid * heavy inflammable air *carbonated hydrogene * carbonic oxide / protoxide ** William Cruickshank discovered the composition of carbon monoxide and named it gaseous oxide of carbon. Cruickshank recognized water and hydrogen were not a constituent of the combustible base which contained the same ingredients as carbonic acid, although containing less oxygen. **Carbonic oxide was identified in the intestine of cattle in the 1800s, marking a trace origin for endogenous carbon monoxide. *carbonous oxyd **The name carbonous oxyd relative to carbonic acid was once considered analogous to nitrous oxide to nitric acid based on the oxide not having sufficient oxygen to form the acid.

Hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

Hydrogen was initially thought to be toxic based on experiments by Lavoisier, however, the purity of the hydrogen was taken into question when later experiments discovered hydrogen to effectively treat measles in the 1790s. * factitious air (Boyle) * hydrogene – means "water former" from hydro- and gene- * inflammable air * inflammable gas * base of inflammable air *zincic inflammable air *martial inflammable air

Hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist ...

* sulphurated hydrogene **therapeutic application of H2S for gastrointestinal disorders dates as early as 1806 *hepatic air

Methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

*marsh gas/air *carburetted hydrogen *light carburetted hydrogen *heavy inflammable air *dicarburet of hydrogen *fire-damp *gas of the acetates

Nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

* azotic air * azote – means lifeless, or a-zote for "not life", generally regarded as the solid constituent whereas azotic gas was the gaseous form. * phlogisticated air *atmospherical memphitic gas * mephitis *nitrogene * base of mephitis *stickstoffgas

Nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or factitious air, among others, is a chemical compound, an Nitrogen oxide, oxide of nitrogen with the Chemical formula, formula . At room te ...

*factitious air ( Davy) *dephlogisticated nitrous air *protoxide of nitrogen *hypo-nitrous oxide *gaseous oxide of azote

Oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

Blood has been understood to absorb and deliver oxygen since the mid-1790s. *vital air *highly respirable air *pure air *phosoxygen *dephlogisticated air *empyreal air *base of vital air *oxy-gene means acid-former or acid-expression, once thought all acids contained oxygen.

Miscellaneous

* animal inflammable air

Therapeutics

The study of these airs interfaced with

phlogiston theory The phlogiston theory, a superseded scientific theory, postulated the existence of a fire-like element dubbed phlogiston () contained within combustible bodies and released during combustion. The name comes from the Ancient Greek (''burnin ...

. The therapeutic potential of factitious airs were widely investigated with significant contributions by

Thomas Beddoes Thomas Beddoes (13 April 176024 December 1808) was an English physician and scientific writer. He was born in Shifnal, Shropshire and died in Bristol fifteen years after opening his medical practice there. He was a reforming practitioner and te ...

James Watt James Watt (; 30 January 1736 (19 January 1736 OS) – 25 August 1819) was a Scottish inventor, mechanical engineer, and chemist who improved on Thomas Newcomen's 1712 Newcomen steam engine with his Watt steam engine in 1776, which was f ...

James Lind James Lind (4 October 1716 – 13 July 1794) was a Scottish physician. He was a pioneer of naval hygiene in the Royal Navy. By conducting one of the first ever clinical trials, he developed the theory that citrus fruits cured scurvy. Lind ...

Humphry Davy Sir Humphry Davy, 1st Baronet (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several Chemical element, e ...

, and others at the Pneumatic Institution. Georgiana Cavendish, Duchess of Devonshire (related to Henry through marriage) had a profound interest in chemistry with interest in Henry's research in

pneumatic chemistry In the history of science, pneumatic chemistry is an area of scientific research of the seventeenth, eighteenth, and early nineteenth centuries. Important goals of this work were the understanding of the physical properties of gases and how the ...

. She played a pivotal role in advancing the study of factitious airs through partnering with

to establish the Pneumatic Institution.

Tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

was a primary disease physicians had attempted to treat with factitious airs, particularly since

's daughter died of the disease. John Carmichael had reported successfully treating a patient suffering from

tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

using hydrocarbonate. This application of factitious air was pioneering research relevant to the modern era as

carbon monoxide Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

currently has preclinical evidence of treating ''

Mycobacterium tuberculosis ''Mycobacterium tuberculosis'' (M. tb), also known as Koch's bacillus, is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' ha ...

'' infection progression by inducing dormancy, stimulating host immune response, and ameliorating host inflammation.

References

{{reflist, 30em 17th-century neologisms Robert Boyle 18th century in medicine History of pharmacy History of chemistry Misidentified chemical elements Gases