Development of the Periodic Chart

Lothar Meyer

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MeyerJulius Lothar Meyer (born 1830, died 1895; ←portrait at left), born at Varel on the Jade in the Grand Duchy of Oldenburg, became one of Germany's most prominent chemists.  His father was a physician and his mother often assisted at operations.  Lothar was consider less than a robust child, so was provided an outdoor education under the guidance of the chief gardener at the Grand Duke of Oldenburg's summer palace.  He developed a sturdy body coupled with an interest in nature.  Both Lothar and his brother Oskar Emil received medical educations but chose other professions.  Lothar earned his degree in medicine from Würzburg in 1854.  He then went to Heidleberg to study with Bunsen and Kirchhoff (who were discovering new chemical elements by analyzing their emission spectra). In 1858 he became a privatdocent in physics and chemistry at Breslau where he was joined by his brother as a professor of mathematics and mathematical physics.

In 1864 Meyer published Die Moderne Theorien der Chemie... which established a wide reputation.  He had attended the first International Chemical Congress in 1860 at Karlsruhe and had been impressed by Stanislao Cannizzaro's proposed solution to atomic weights.  In Die Moderne Theorien der Chemie... Meyer adopted and popularized the Avogadro Hypothesis as proposed by Cannizzaro.  His text contained three tables with elements grouped in columns by their valence.  The tables do not appear in the section on classification of elements, but rather in a section entitled The Nature of Atoms: Evidence Opposing their Simplicity.  At a time when much of the world was still debating whether atoms really exist as the smallest entitites of matter, Meyer pondered the possible nature of atoms.  His table with vertical columns of families of similar valence elements had increasing atomic weight elements in horizontal rows.  For the empty position between Silicon and Tin, Meyer applied half the weight difference above and half below but didn't postulate a missing element.  Meyer was struck by the periodicities of physical properties.

Meyer's Valence Table
Die Moderne Theorien der Chemie... [1864]
4 werthig 3 werthig 2 werthig 1 werthig 1 werthig 2 werthig
Li = 7.03 (Be = 9,3?)
Differenz = --- --- --- --- 16,02 (14,7)
C = 12,0 N = 14,04 O = 16,00 Fl = 19,0 Na = 23,05 Mg = 24,0
Differenz = 16,5 16,96 16,07 16,46 16,08 16,0
Si = 28,5 P = 31,0 S = 32,07 Cl = 35,46 K = 39,13 Ca = 40,0
Differenz = 89,1/2 = 44,55 44,0 46,7 44,51 46,3 47,6
--- As = 75,2 Se = 78,8 Br = 79,97 Rb = 85,4 Sr = 87,6
Differenz = 89,1/2 = 44,55 45,6 49,5 46,8 47,6 49,5
Sn = 117,6 Sb = 120,6 Te = 128,3 J = 126,8 Cs = 133,0 Ba = 137,1
Differenz = 89,4 = 2*44,7 87,4 = 2*43,7 --- --- 71 = 2*35,5 ---
Pb = 207,0 Bi = 208,0 --- --- (Tl = 204?)

In 1868 Meyer went to Karlsruhe Polytechnicum which during the war between Germany and France was used by the army as a hospital.  He applied his medical training as an army surgeon and was awarded a medal at the close of the war.  In 1869 a German abstract of a March publication revealed that a Russian chemist, Dmitri Mendeléeff, has published a somewhat similar periodic table.  The abstract shows the table accompanied by eight conclusions from the end of the Russian paper.  In December 1969 Meyer arranged 56 elements in a valence table that was published in 1870 with a series of graphs showing the periodic repetition of atomic volumes and other properties verses atomic weights.

Meyer: [1870]
Series.
1. Li Be
2. B C N O F Na Mg
3. Al Si P S Cl K Ca
4.     -     Ti     V     Cr   Mn Fe Co,Ni     Cu     Zn
5. - - As Se Br Rb Sr
6. - Zr Nb Mo Ru Rh Pd Ag Cd
7. In Sn Sb Te I Cs Ba
8. - - Ta W Os Ir Pt Au Hg
9. Tl Pb Bi - - - -

In 1871 a German translation of Mendeléeff's longer paper appeared which gave precise predictions for three missing elements.

In 1876 Lothar Meyer became a professor of chemistry at the University of Tübingen.  Meyer died in April 1895.


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page created 23 March 2002; addition 30 March
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