| Julius Lothar von Meyer | |
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Julius Lothar Meyer
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| Born | August 19, 1830 Varel |
| Died | April 11, 1895 Tübingen |
| Fields | Chemistry |
| Institutions | University of Tübingen |
| Known for | Periodic table of chemical elements |
| Influences | Robert Bunsen |
Julius Lothar von Meyer (August 19, 1830 - April 11, 1895) was a German chemist. He was contemporary and competitor of Dmitri Mendeleev to draw up the first periodic table of chemical elements. Some five years apart, both Mendeleev and Meyer worked with Robert Bunsen.
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He was born in Varel, at that time belonging to the Duchy of Oldenburg, now part of Germany, the son of Friedrich August Meyer, a physician, and Anna Biermann. After high school (Altes Gymnasium Oldenburg AGO) he went to study medicine first at Zürich University in 1851, and then, two years later, at the University of Würzburg, where he had Rudolf Virchow as his teacher in pathology. The influence of C. F. W. Ludwig, under whom he studied at Zürich, decided him to devote his attention to physiological chemistry, and therefore he went, after his graduation (1854), to Heidelberg, where R. Bunsen held the chair of chemistry. There he was so influenced by G. R. Kirchhoff's mathematical teaching that he took up the study of mathematical physics at Königsberg under F. E. Neumann. In 1859 he became privat-docent in physics and chemistry at Breslau. In the preceding year, he had graduated as Ph.D. with a thesis on the action of carbon monoxide on the blood.[1] In 1866 he accepted a post in the School of Forestry at Neustadt-Eberswalde, but soon moved to Carlsruhe Polytechnic.[2] He married Johanna Volkmann on August 16, 1866.
Meyer is best known for the share he had in the periodic classification of the elements. He noted, as did J. A. R. Newlands in England, that if they are arranged in the order of their atomic weights they fall into groups in which similar chemical and physical properties are repeated at periodic intervals; and in particular he showed that if the atomic weights are plotted as ordinates and the atomic volumes as abscissae, the curve obtained presents a series of maxima and minima, the most electro-positive elements appearing at the peaks of the curve in the order of their atomic weights.[2]
His book on Die modernen Theorien der Chemie, which was first published in Breslau in 1864,[2] has an early version of the periodic table containing 28 elements classified into 6 families by their valence — the first time that elements had been grouped and ordered according to their valence. Work on organizing the elements by atomic weight had hitherto been stymied by inaccurate measurements of the atomic weights.
Mendeleev published his periodic table of all known elements (and predicted several new elements to complete the table, plus some corrected atomic weights) in 1869. Working completely independently, a few months later, Meyer published a revised and expanded version of his 1864 table, virtually identical to that published by Mendeleev (Meyer had been sent a copy of Mendeleev's table earlier, Mendeleev sent it to all well known chemists of those times) and a paper showing graphically the periodicity of the elements as a function of atomic weight. As well as other chemists, Meyer was doubtful about Mendeleev's periodic law, and he criticized Mendeleev for 'changing existing elements' atomic weights, only regarding possibility of periodical law in its structure', but Mendeleev's work provided significant support, particularly when the new elements were found as predicted and remeasured atomic weights accorded with those predicted.
In 1882, Meyer received from the Royal Society, at the same time as Mendeleev, the Davy Medal in recognition of his work on the Periodic Law.
Meyer's contributions also included the concept that the carbon atoms in benzene were arranged in a ring, although he did not propose the alternation of single and double bonds that later became included in the structure by August Kekulé.
During the Franco-German campaign, the Polytechnic was used as a hospital, and he took an active part in the care of the wounded. In 1876, Meyer became the first Professor of Chemistry at the University of Tübingen, where he served until his death there.[2]