Elementymology & Elements Multidict

memory peg	Odorless, colorless, very 'light' gas melting point -259 °C; -434 °F boiling point -253 °C; -423 °F density 0.000090 g/cc; 0.0056 pounds/cubic foot
Hydrogen: 1766 Henry Cavendish, England Deuterium: 1932 Harold C. Urey, et al., New York, USA Tritium: 1935 Ernest Rutherford, et al., Cambridge, England
ΰδωρ (hydōr) = water + γεινομαι (geinomai) = to engender, bring forth ⇒ bringing forth water (Greek), named by Antoine Lavoisier in 1793

Since the ancient Greeks, all gases were regarded as a single elementary substance, air, although perhaps tainted by other elements. Hydrogen was observed and collected long before it was recognized as a unique gas. The nature of hydrogen began to emerge around the 16th century when the Swiss alchemist Paracelsus (Philippus Aureolus Theophrastus Bombastus von Hohenheim, 1493-1541) described a gaseous product arising when iron was dissolved in sulfuric acid. He described this product as "an air which bursts forth like the wind". Robert Boyle had before 1671 dissolved iron in dilute hydrochloric acid and prepared what he described as the inflammable solution of Mars [Iron]. Joseph Priestley (1733-1804), and in general all the authors until 1783, used the term "inflammable air" to describe this gas as to hydrocarbons, hydrogen sulphite, carbon monoxide and other combustible gases.

Henry Cavendish (1731-1810) collected the gas over Mercury, subjected it to systematic study, and reported his findings in 1766 to the Royal Society. He made no claim to having discovered Hydrogen, but he was the first to distinguish Hydrogen from other gases by the descriptive term "inflammable air from the metals". Probably this distinction was a major contribution to Antoine Lavoisier's belief that each gas is a separate element.

In 1783 it was named hydrogène by Lavoisier, because when hydrogen burns, water is produced.

Hydrogenium (and its derivations in several modern languages) is a combination of the Greek words ΰδωρ [hydōr] = water, and from Greek γεινομαι (geinomai) = to engender, bring forth, (cf. Oxygen, where is made clear that in naming this element, Lavoisier referred to γεινομαι and not to γενναω (gennaō), to produce, as was assumed later). It means "making water".

• German: Wasser = water, and Stoff = material.
• Dutch: water = water, and stof = material.
  
• Slavic languages: voda = water.
• Lithuanian: vanduo = water.
  
• Japanese: 水 = Chinese character for water and 素 "so" (elementary, principle, naked, or uncovered).

• ¹H is Protium, mass number of 1 and has a single proton in the nucleus. The name is derived from the Greek πρωτος [prōtos] = the first.
• ²H is Deuterium, symbol D, mass number of 2, and has one proton and one neutron in the nucleus. The name is derived from the Greek δευτερος [deuteros] = the second.
  In England the name Diplogenium (from the Greek διπλους [diplous] = double] was used, also with symbol D.
• ³H is Tritium, symbol T, mass number of 3, and has one proton and two neutrons in its nucleus. The name is derived from the Greek τριτος [tritos] = the third.

1. 8 Dec. 1933: R.W. Wood, John Hopkins University, "Suggested Nomenclature for Heavy Hydrogen and its Compounds" (note).
   The name deuterium would complicate the matter, for it suggest a new element instead of an isotope. He suggests to speak of bar-hydrogen and to write Ħydrogen, symbol Ħ (Ħ should be a H with a bar above, I am glad Wood's suggestion did not make it since that symbol is not on a keyboard).
2. 29 Dec. 1933: Harold C. Urey; F. G. Brickwedde; G. M. Murphy, "Names for the Hydrogen Isotopes" (note).
   In their reaction on Wood's letter, Urey, Brickwedde and Murphy wrote that "(we) considered exactly this name and symbol before we published the suggestion of the name deuterium for the heavy isotope, and protium for the light isotope." It was because of the difficulty of naming the compounds that they discarded that name and symbol. On Wood's objection that it seemed a new element, they wrote that after discussions with organic chemists it appeared almost necessary to name some of the compounds with H² as though it was a foreign element.
3. 29 Dec. 1933: Frank C. Whitmore, Pennsylvania State College, "Suggested Nomenclature for Heavy Hydrogen and its Compounds" (note).
4. 9 Febr. 1934: William D. Harkins, University of Chicago, "Nomenclature for the Isotopes of Hydrogen (Proto- and Deuto-Hydrogen) and Their Compounds" (note).
   The fundamental difficulty of the nomenclature suggested by Urey c.s. and Wood was that "it specifies an atomic species by a single name, while by any simple numerical system two independent variables are involved." These two variables are the atomic number and the isotopic number. Because there were at Harkins' time 91 elements known, and some of them with 11 isotopes, any system of individual names, without reference to which element it belongs, is confusing. Harkins finds a solution in a system where the names have a relation to numerical designations. He takes hydrogen as an example: the element of atomic weight 1 is represented by (1,-1), in which 1 is the atomic and -1 the isotopic number. The symbol than is H^-1 (he preferred H with a superscript 1 with a dash above, which I can not reproduce in html). The name should be Protohydrogen. Hydrogen of atomic weight 2, represented by (1,0) is H⁰ or Deutohydrogen (the more correct form Deuterohydrogen he considered too long). Hydrogen with atomic weight 3 would ne named Tritohydrogen. He also had heard of Rutherford's name diplogen (from διπλους [diplous] = double). This name should be only acceptable for H² when H¹ is named Haplogen or Haplohydrogen (from απλους [haplous] = single).
5. 9 Febr. 1934: J.B. Ficklen, Hartford, Conn., "Isotopic Nomenclature" (note).
   In the same issue of Science J.B. Ficklen wrote that as isotopes with mass 1 and 2 are named "protinium" (Ficklen's error?) and "deuterium" respectively, an isotope with mass 86 would be named "hakloskyhogdoekostium (εκτος και ογδοηκοστός)", and it would be unclear if it is an isotope of Strontium or of Krypton [Ficklen made his point, but his Greek was not so good: firstly, the transcription should have been hektosky-ogdoekostium, and further, 86 in Greek is ογδο(η)κοστα εξι, giving an isotope name as "ogdokosta-hexium"].
   
6. 16 Febr. 1934: Willis A. Boughton, Chemical Laboratories, Harvard University, "Naming Hydrogen Isotopes" (note).
   A much simpler form suggested: Hydrogen-p and Hydrogen-d with symbols Hp and Hd for Protium and Deuterium respectively.
   
7. 2 March 1934: Ross Aiken Gortner, University of Minnesota, "A Suggestion Regarding the Chemical Formulae of Compounds Containing Hydrogen and Oxygen Isotopes" (note).
   Gortner agreed with the names Protium, Deuterium and Trition, but not with the suggested symbols Pm and D (and probably Tr). Since Deuterium is referred to as "heavy hydrogen" its symbol should be a bold-faced letter H, and if H³ -Tritium- is ever produced, its symbol can be a bold-faced Old English letter H (Science did not have this font, and thus printed simply H).
   
8. 9 March 1934: Robert S. Mulliken, "Symbols and Names for the Hydrogen Isotopes" (note).
   Muliken started to described the discussion as one between conflicting ideals:
   1. maximum brevity, simplicity, and euphony,
   2. maximum explicitness, completeness and consistency,
   3. principle that well-established nomenclature should not be too hastily set aside; and, if is replaced, the new nomenclature should not contain old names with new meanings.
   He suggested to name isotopes like plants and animals. "We speak of Quercus alba and Q. rubra; why not Hydrogenium protium and Hydrogenium deuterium as complete systematic names for the hydrogen isotopes?" For the symbols of H. protium and H. deuterium he discusses several possibilities: a single letter (ideal a, but not b) or Hp and Hd look to much to new elements; better is H^p and H^d, or simpler Hπ and Hδ, but finally preferred the more simpler form as Π and Δ. The use of Greek letters makes it clear it are symbols for isotopes, not elements, thus it not violates ideal b. Finally, he recommended the names hydrogen (H), (hydro)protium (Π) and (hydro)diplium (Δ), for the latter he follows Rutherford's name "diplon" for the H²-particle, but adds that there is no sufficient reason to give ip [(hydro)]deuterium (in a note, he adds that also the meaningless name delton for the particle - and (hydro)deltium for the isotope - would not be unpleasant).
9. 23 March 1934: C. E. Waters, Washington, D.C., "The Case of Deuterium" (note).
   The whole discussion among chemists is ridiculous in the eyes of zoologists and botanists. These sciences observe the rule of priority: the name first given to a new animal or plant shall be accepted. "This simple principle (...) is either unknown to chemists or is ignored by them." Waters did not admire the name deuterium, and would not select it for his scientific child, but had not bothered to think up another, better of worse. He refers to older discoveries which led not to any discussion, Hevesy named the new element "Hafnium" after the old Latin name of his town, but he could have chosen for the modern name "Copenhagenium", this would have been quite a strain. Just as Hevesy, Urey and his colleagues would have had the right to name the new isotope "newyorkium" (since "columbium" in already used in the USA), or, just as Hevesy took the old name "eboracum" [should have been "novum-eboracum", PvdK). Concerning the symbol, Waters found Gortner's suggestion for a bold H a problem for the typist and the lecturer writing it on a blackboard. For their sake, "one can almost wish that tritium will not be discovered, because Old English letters are bad enough when they are printed."
10. 1 June 1934: Terminologist, "Terminology of Isotopes" (note).
    The chemist (?) using the pseudonym Terminologist suggested to give to each isotope an alphabetic letter in the order of the abundance. Deuterium then would be b-hydrogen, but may have as an exception a distinct name because it shows the greatest physical difference for an isotope. In Crane's report (see next) Terminologist's names are slightly adjusted to hydrogen-a and hydrogen-b and given the symbols Ha and Hb.
11. 27 July 1934: E. J. Crane, "Nomenclature of the Hydrogen Isotopes and Their Compounds" (note).
    Finally, the question was studied by the Nomenclature, Spelling and Pronunciation Committee of the American Chemical Society. The committee's chairman Crane reported in an article in Science. Concerning the names of isotopes, the committee followed the choice of the discoverers, Protium and Deuterium (they did not want to say anything on Tritium until it was discovered). Concerning the symbols, the members of the committee were divided, on third liked H and H², one third H and D, and the other third Hd (which they found better than Hd, see Muliken) and Hb (see Terminologist).

In a review of the discovery, Hugh S. Taylor discusses the christening of the isotopes in the Scientific Monthly of October 1934 (note):

Shortly after the isolation was accomplished, Urey, Brickwedde and Murphy christened the isotopes (note); hitherto this had not been necessary with isotopes since there had been no chemistry of separate isotopes to be considered. The discoverers of heavy hydrogen suggested, for hydrogen of mass 1, the name protium, since this would conform with current usage of the name proton for the nucleus of the hydrogen atom. For the isotope of mass two they proposed the name deuterium, which, for the nucleus of this atom, suggests deuteron, or, more briefly, deuton, the nucleus of mass 2 and unit positive charge. They also suggested that, if the isotope of mass 3 were discovered, the name tritium might be considered.
These names have found general acceptance, except in England, where, following a suggestion from Lord Rutherford's laboratory, the name "diplogen" has been employed. The best excuse for this latter is that it gives "diplon" instead of deuton, which latter does not find favor with the English scientists who, with colds in their heads in winter time, may confuse deuton with the "neutron" the particle of mass 1 and zero charge.
Considerable discussion has arisen as to the symbols to be employed. Previous custom has sanctioned H¹, H² and H³ for the symbolic representation. There is, however, an increasing use of H for H¹, of D for H² and of T for H³. Fortunately, D and T have not hitherto been used as symbols for any elements; also, D stands, equally well in England and elsewhere, for both, deuterium and diplogen.

• Wasserstoff. Gmelins Handbuch der anorganische Chemie, 8. Aufl.; System-Nummer 2 (1927).
• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Henry M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 177-185.
• Names for Hydrogen species. From the JCBN/NC-IUB Newsletter 1989 (on-line).