"Remarks on the Discovery of Gallium" ++Never-bound signatures of the Philosophical Magazine++ Dmitri Mendeleev. ++From Hypothesis to Law++ Chemistry

Dmitri Mendeleev. "Remarks on the Discovery of Gallium" never-bound signatures of the Philosophical Magazine, series 5, no 7., Supplement vol 1, London, 1876, pp 497-576, with the Mendeleev on pp 542-546. (Mendeleev is spelled Mendelejeff here with the running title of "M.D. Mendelejeff on the discovery of Gallium".) The supplement is complete in 6 unbound signatures which are also uncut and unopened. Scarce in this format. [++] The Mendeleev paper was printed in 1876 a year after Lecoq de Boisbaudran's discovered gallium (Mendeleev's predicted "eka-aluminium"). Boisbaudran's paper appeared in "Comptes Rendus de l'Academie des Sciences", vol 81, No 12; a longer and more complete paper appeared in 1877 in "Annales de Chimie et de Physique". [++] In this paper Mendeleev wrote on how Gallium's properties were a very close fit to what his table predicted they would be, therefore providing strong experimental evidence for the validity of the periodic table. (His paper in English follows closely the French appearance of "Remarque à propos de la découverte du gallium" in the "Comptes Rendus" vol 81, 1875, pp. 969-972 .) "In 1875 Boisbaudran spectroscopically discovered a new element, gallium, which he found in zinc blend from a mine in Hautes-Pyrénées. Continuing his work in Wurtz's laboratory in Paris, he was a able to obtain the free metal by electrolysis of a solution of the hydroxide in potassium hydroxide. Gallium, Boisbaudran realized, was the "eka-aluminum" predicted by Mendeleev, and was the first of Mendeleev's predicted elements to be isolated. Boisbaudran's finding thus provided valuable evidence for the validity of Mendeleev's periodic classification of the elements."--Complete DSB online. [++] "Although Lecoq de Boisbaudran objected to this interpretation, he made a second determination of the specific weight of gallium and confirmed that such was indeed the case. From that moment the periodic law was no longer a mere hypothesis, and the scientific world was astounded to note that Mendeleev, the theorist, had seen the properties of a new element more clearly than the chemist who had empirically discovered it. From this time, too, Mendeleev's work came to be more widely known".--Complete DSB online.