Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
Jump to content

Charles Janet

From Wikipedia, the free encyclopedia
Charles Janet
Janet around 1925
Born
Charles Janet

(1849-06-15)15 June 1849
Paris
Died7 February 1932(1932-02-07) (aged 82)
Voisinlieu (Beauvais)
Alma materÉcole Centrale Paris[1]
Known forLeft-step periodic table of chemical elements
Spouse
Berthe Marie Antonia Dupont
​
​
(m. 1877)​
[1]
Children7[2]
Parents
  • Joseph Augustin Janet (1814–1871)[1] (father)
  • Sophie Pauline Adèle Ganié (1821–1905)[1] (mother)
Scientific career
Fields
Signature

Charles Janet (French: [ʃaʁl ʒanɛ]; 15 June 1849 – 7 February 1932) was a French engineer, company director, inventor and biologist. He is also known for his left-step periodic table of chemical elements.[3]

Life and work

[edit]

Janet graduated from the École Centrale Paris in 1872,[1]: 57  and worked for some years as a chemist and engineer in a few factories in Puteaux (1872), Rouen (1873–74), and Saint-Ouen (1875–76).[1]: 61–65  He was then employed by Philippe Alphonse Dupont, at Société A. Dupont & Cie, a factory that produced bone buttons and fine brushes. He married Berthe Marie Antonia Dupont, the daughter of the owner, in November 1877, and worked there for the rest of his life, finding time for research in various branches of science.[1]

Janet's collection of 50,000 fossils and other specimens was dispersed after his death.[2][4] His studies of the morphology of the heads of ants, wasps and bees, and his micrographs were of remarkable quality.[5] He also worked on plant biology and wrote a series of papers on evolution. He was an inventor and designed much of his own equipment, including the formicarium, in which an ant colony is made visible by being formed between two glass panes.[6] In 1927 he turned his attention to the periodic table and wrote a series of six articles in French that were privately printed and never widely circulated. His only article in English was poorly edited and gave a confused idea of his thinking.[7]

Scientific work

[edit]

In parallel with his professional activities, Janet began a university course at the Sorbonne in 1886. He became a member of the French Entomological Society and the French Zoological Society. First in his class, he began a thesis on ants and obtained his doctorate in natural sciences in 1900. Before the end of his studies, the French Academy of Sciences regularly published his research in its reports and awarded him the Thore Prize in 1896.[8][9] In 1899, he was elected president of the French Zoological Society. In 1900, he improved his artificial nests and showed them at the Universal Exhibition in Paris.[10] He attracted the interest of journalists who described the public's interest in ants. In 1909, the French Academy of Sciences awarded him the Cuvier Prize[11] for his work in zoology.

Geology and paleontology

[edit]

Janet explored the Paris Basin and especially its chalk.[12] At the request of Edmond Hébert and his geology laboratory at the École Pratique des Hautes Études, he organized a geological excursion[13] around Beauvais for the students of the Sorbonne University and the MNHN. He assembled a collection of fossil and prehistoric pieces. He estimated it contained around 50,000 items.[2] A large part of the collection included fossils from regional deposits that have now disappeared or are almost inaccessible, such as the Bracheux Sands (partially covered by the expansion of the city of Beauvais). He also developed a method for preserving the fragile shells of these geological layers.[14]

Other local tertiary deposits are represented, such as the Ypresian and Lutetian from the regions of Chaumont-en-Vexin, Parnes, Grignon, Chambors, and Mouy. The collection also included numerous echinoderms, for which he co-wrote an article with Lucien Cuénot.[15] In the chalk of the Beauvais area, he discovered three new species of belemnites.[16] These are Actinocamax grossouvrei, Actinocamax toucasi, and Actinocamax alfridi.[17]

Entomology

[edit]
Artificial ant nest.

Janet was particularly interested in social hymenoptera.

In 1894, he observed a hornet's nest from its origin until the death of the last worker.[18] During these 5 months of observations, he discovered the trophallaxis of hornet larvae.[19][20] He invented a vertical artificial nest that remained a tool for entomologists for a long time. This type of nest allowed him to understand how some insects live at the expense of ants. He surprised, for example, the silverfish stealing the droplet of sugary liquid exchanged between two ants.[21] He then performed in-depth studies on the internal anatomy of ants, where he endeavored to show their organization in metameres.[22] In the young ant queen, he discovered the transformation of flight muscles after she tore off her wings. He demonstrated that these muscles evolve into lipid cells, providing the necessary energy for this queen who does not feed during the long months it takes to establish her colony.[23]

In the end, 22 of the 24 notes he proposed to the French Academy of Sciences were related to social insects. He gradually sought to link ethology with insect physiology through histological sections.[5] Maurice Maeterlinck wrote:

It is necessary to mention the engineer Charles Janet, whose countless studies, research, communications, monographs, precise, clear, impeccable, and adorned with anatomical plates that have become classics, have continued, for nearly fifty years, to enrich myrmecology as well as many other sciences. He is one of those great workers to whom justice is done only after their death.[24]

Botany

[edit]

Building on his studies of insect metamerism, Janet sought to conceive a common ancestor for animals and plants. According to Janet, metazoans came from colonies of flagellated protozoa. Janet studied Volvoxs. For him, the Volvox,[25] which has not evolved since its divergence from phyto-flagellates, is a living fossil that strongly recalls the beginnings of the animal kingdom.

Orthobiontic formula of the ant (1925)

A few years later, a theory called orthobiontics[26] emerged in which Janet outlined an organization plan for living beings.

Ultimately based on excessive theorization that takes precedence over his observations, undermined by a text filled with complex neologisms, all translated into mathematical language, this theory remained inaccessible. It was also extremely poorly received in the Revue générale des Sciences pures et appliquées (General Review of Pure and Applied Sciences).[27]

Chemistry

[edit]
Spiral atomic classification (April 1928)

At the age of 78, Janet began to research atoms. He was interested in the properties of atoms and the organization of their nuclei. To synthesize his ideas, he reflected on a periodic classification of atomic elements.[28] For him, their physico-chemical properties are intimately linked to their arithmetic and graphical arrangement.[29]

Moreover, the perfect regularity he observes at all levels of his table is, for Janet, proof that he has discovered the correct distribution law. In 1930, he even proposes to verify it by aligning his classification with the very recent quantum theory.[30] In doing so, he is the first to state the rule that describes the order in which electrons fill the subshells of an atom. This rule, later rediscovered, is commonly called the Madelung rule since 1936 among English speakers or the Klechkowski rule (of Soviet origin in 1962 and in use in France). Confidentially, Janet's classification will remain completely ignored in France. Thanks to these astonishing spiral figures, it will reappear 40 years later among American chemists[31] before a new eclipse. It has only been considered a valid alternative[32] to the famous Mendeleev's classification under the name of Left Step Table for about a decade. Eric Scerri, an American historian (UCLA), has popularized Janet's form in magazines such as Scientific American[33] or Pour la Science.[34] He also devotes an entire chapter of his latest work[35] to Charles Janet, whom he sees as a minor contributor in terms of fame, but major in terms of ideas.

Periodic table

[edit]

Janet started from the fact that the series of chemical elements is a continuous sequence, which he represented as a helix traced on the surfaces of four nested cylinders. By various geometrical transformations he derived several striking designs, one of which is his "left-step periodic table", in which hydrogen and helium are placed above lithium and beryllium. It was only later that he realized that his arrangement agreed perfectly with quantum theory and the electronic structure of the atom. He placed the actinides under the lanthanides twenty years before Glenn Seaborg, and he continued the series to element 120.

Janet's table differs from the standard table in placing the s-block elements on the right, so that the subshells of the periodic table are arranged in the order (n − 3)f, (n − 2)d, (n − 1)p, ns, from left to right. There is then no need to interrupt the sequence or move the f block into a 'footnote'. He believed that no elements heavier than number 120 would be found, so he did not envisage a g block. In terms of atomic quantum numbers, each row corresponds to one value of the sum (n + ℓ) where n is the principal quantum number and ℓ the azimuthal quantum number. The table therefore corresponds to the Madelung rule, which states that atomic subshells are filled in the order of increasing values of (n + ℓ). The philosopher of chemistry Eric Scerri has written extensively in favor of Janet's left-step periodic table, and it is being increasingly discussed as a candidate for the optimal or most fundamental form of the periodic table.[36]

Left-step periodic table (by Charles Janet)
f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 d1 d2 d3 d4 d5 d6 d7 d8 d9 d10 p1 p2 p3 p4 p5 p6 s1 s2
1s H He
2s Li Be
2p 3s B C N O F Ne Na Mg
3p 4s Al Si P S Cl Ar K Ca
3d 4p 5s Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr
4d 5p 6s Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te  I  Xe Cs Ba
4f 5d 6p 7s La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra
5f 6d 7p 8s Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og Uue Ubn
f-block d-block p-block s-block
This form of periodic table is congruent with the order in which electron shells are ideally filled according to the Madelung rule, as shown in the accompanying sequence in the left margin (read from top to bottom, left to right). The experimentally determined ground-state electron configurations of the elements differ from the configurations predicted by the Madelung rule in twenty instances, but the Madelung-predicted configurations are always at least close to the ground state. The last two elements shown, elements 119 and 120, have not yet been synthesized.

Janet also envisaged an element zero whose 'atom' would consist of two neutrons,[37] and he speculated that this would be the link to a mirror-image table of elements with negative atomic numbers – in effect anti-matter. He also conceived of heavy hydrogen (deuterium). He died just before the discovery of the neutron, the positron and heavy hydrogen.[3] His work was championed most notably by Edward G. Mazurs.[31]

Family

[edit]

Armand Janet,[38]: 5  Charles's brother was also an engineer and entomologist. Armand became known as a lepidopterist[5] and was president of the Société entomologique de France in 1911.[38]

References

[edit]
  1. ^ a b c d e f g Casson, Loïc (30 March 2018). De la fourmi à l'atome: les sciences naturelles vues et vécues par Charles Janet (1849-1932) [From ants to atoms: the natural sciences seen and experienced by Charles Janet] (PhD thesis) (in French). PSL Research University; EHESS - Paris; Centre Alexandre Koyré - CRHST.
  2. ^ a b c Casson, Loïc (March 2008). "Charles Janet, un savant oublié" [Charles Janet, a forgotten scientist]. Academic Society of Oise (in French). Retrieved 22 February 2023.
  3. ^ a b Stewart, Philip (April 2010). "Charles Janet: unrecognized genius of the Periodic System". Foundations of Chemistry. 12: 5–15. doi:10.1007/s10698-008-9062-5. S2CID 171000209.
  4. ^ Casson, Loic (2008). "Notice biographique sur la vie et l'oeuvre de Charles Janet" [Biographical note on the life and work of Charles Janet]. Bulletin de la Société Académique de l'Oise (in French).
  5. ^ a b c Billen, Johan; Wilson, Edward O. (2008). "Social insect histology from the nineteenth century: The magnificent pioneer sections of Charles Janet". Arthropod Structure & Development. 37 (3): 163–167. CiteSeerX 10.1.1.186.5112. doi:10.1016/j.asd.2007.07.002. PMID 18342262.
  6. ^ Janet, Charles (1893). "Appareil pour l'élevage et l'observation des fourmis" [Apparatus for the breeding and observation of ants]. Annales de la Société Entomologique de France. 62: 467.
  7. ^ Janet, Charles (June 1929). "The helicoidal classification of the elements". Chemical News. 138: 372–374, 388–393.
  8. ^ Janet received the Thore Prize 30 years after Jean-Henri Fabre, who was its first recipient.
  9. ^ Text of the Thore Prize awarded to Janet
  10. ^ Henry de Varigny (23 July 1900). "Promenade at the Exhibition: with the ants". Le Temps (in French): 3.
  11. ^ Text of the Cuvier Prize awarded to Janet
  12. ^ Charles Janet (2 November 1891). "Note on the conditions under which the chalk deposit in the Anglo-Parisian Basin was formed". Bulletin de la Société Géologique de France (in French). 19: 903–1014.
  13. ^ Charles Janet; Jules Bergeron (1883). "Geological excursions around Beauvais". Mémoires de la Société académique de l'Oise (in French). 12: 249–273.
  14. ^ Charles Janet (1894). "Artificial transformation of the friable limestone of the fossils from the Bracheux Sands into gypsum". Bulletin de la Société Géologique de France (in French). 22: 83.
  15. ^ Charles Janet; Lucien Cuénot (1891). "Note on multiple genital openings, on the extension of the madreporic pores outside the madreporite, and on the terminology of the apical apparatus in sea urchins". Bulletin de la Société Géologique de France (in French). 19: 295–305.
  16. ^ Charles Janet (10 June 1891). "Note on three new Senonian belemnites". Bulletin de la Société Géologique de France (in French). 19: 716–719.
  17. ^ The holotypes from the Janet collection can be seen in the national inventory of paleontological types and figured specimens. This is the Trans’Tyfipal Archived 25 June 2018 at the Wayback Machine database, which inventories type and figured specimens from paleontology collections preserved in French universities and museums.
  18. ^ Charles Janet (1895). "On Vespa crabro. History of a nest from its origin". Mémoires de la Société Zoologique de France. 8: 1–140.
  19. ^ Wheeler, William Morton (1926). Les sociétés d'insectes: leur origine, leur évolution [Insect societies: their origin, their evolution] (in French). Paris: G. Doin. p. 280.
  20. ^ Wheeler, William Morton (1928). The social insects: their origin and evolution. London: K. Paul, Trench, Trubner; New York: Harcourt, Brace.
  21. ^ Charles Janet (January 1899). "Sur les rapports des Lépismides myrmécophiles avec les fourmis" [On the relations of myrmecophilous Lepismids with ants]. French Academy of Sciences Weekly Report. 122: 799–803.
  22. ^ Charles Janet (1899). Essai sur la constitution morphologique de la tête de l'insecte [Essay on the morphological constitution of the insect's head]. Paris: G. Carré et C. Naud.
  23. ^ Charles Janet (1906). "Remplacement des muscles vibrateurs du vol par des colonnes d'adipocytes, chez les fourmis, après le vol nuptial" [Replacement of flight vibrator muscles by columns of adipocytes in ants after the nuptial flight]. French Academy of Sciences Weekly Report. 142: 1095–1097.
  24. ^ Maurice Maeterlinck (1930). La vie des fourmis [The life of ants]. Paris: Fasquelle. p. 17.
  25. ^ Charles Janet (1922). Le volvox: deuxième mémoire (in French). Paris: Les Presses Universitaires de France.
  26. ^ Charles Janet (1925). Constitution orthobiontique des êtres vivants. I. Théorie orthobiontique [Orthobiontic constitution of living beings - I. Orthobiontic theory]. Beauvais: Dumontier.
  27. ^ Jean Delphy (1925). "Theories of evolution: the Orthobiont". Revue générale des sciences pures et appliquées. 36 (3): 76–79.
  28. ^ Charles Janet (1928). N. 3 - Essais de classification hélicoïdale des éléments chimiques [Helicoidal classification attempts of chemical elements] (in French). Beauvais: Imprimerie départementale de l’Oise.
  29. ^ Charles Janet (1929). N. 5 - Considérations sur la structure du noyau de l'atome [Considerations on the structure of the atom's nucleus] (in French). Beauvais: Imprimerie départementale de l’Oise.
  30. ^ Charles Janet (1930). N. 6 - Concordance de l'arrangement quantique de base, des électrons planétaires des atomes, avec la classification scalariforme, hélicoïdale, des éléments chimiques [Concordance of the basic quantum arrangement of planetary electrons of atoms, with the scalariform, helicoidal classification of chemical elements] (in French). Beauvais: Imprimerie départementale de l’Oise.
  31. ^ a b Mazurs, Edward G. (1974). Graphic representations of the periodic system during one hundred years. University of Alabama Press.
  32. ^ Philip J. Stewart, « Charles Janet: unrecognized genius of the Periodic System[permanent dead link‍] », Foundations of chemistry, 2009, 8 p.
  33. ^ Eric Scerri (June 2013). "Cracks in the Periodic Table'". Scientific American. 308 (6): 32–37. Bibcode:2013SciAm.308f..68S. doi:10.1038/scientificamerican0613-68. PMID 23729073. S2CID 46138712.
  34. ^ Eric Scerri (October 2013). "Des failles dans le tableau périodique". Pour la Science (in French) (432): 66–71.
  35. ^ Eric Scerri (2016). A tale of seven scientists and a new philosophy of science. New York: Oxford University Press. pp. 149–170.
  36. ^ Scerri, Eric (2021). "Various forms of the periodic table including the left-step table, the regularization of atomic number triads and first-member anomalies". ChemTexts. 8 (6). doi:10.1007/s40828-021-00157-8. S2CID 245540088.
  37. ^ At this time the neutron was an undiscovered particle which had been proposed by Ernest Rutherford and others. See Discovery of the neutron#Rutherford atom
  38. ^ a b Svensson, Erik; Calsbeek, Ryan (17 May 2012). The Adaptive Landscape in Evolutionary Biology. OUP Oxford. pp. 3–5. ISBN 978-0-19-163167-2. Retrieved 8 February 2022.
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Charles_Janet&oldid=1256508537"