Mendeleev and the Rare-Earth Crisis - Philosophy of Chemistry - page 155

11.1.2 Mendeleev s Experimental Research in 1869-1870

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Mendeleev published a trilogy of papers during the first period from 1869 till the
first half of 1870. His first paper On the Correlation Between the Properties of the
Elements and their Atomic Weights was drafted in the second half of February 1869
and put forth his Attempted System as a useful classification of the chemical
elements (Figs. 11.1 and 11.2 ). 12 During the month of August 1869, Mendeleev
wrote a second paper summarising his experimental results Concerning the Atomic
Volumes of Simple Bodies . 13 He then turned to an investigation of the higher salt
forming oxides and presented his results on October 2, 1869 during a meeting of the
Russian Chemical Society in a paper titled On the Quantity of Oxygen in Metal
Oxides and on the Valency of the Elements . 14 If his first paper had served to
announce the discovery of the periodic law (and secure his priority), the remaining
two offered an important illustration (and thus validation) of the concept of
periodicity by his comprehensive study of both the physical and chemical proper-
ties of the elements.
Notwithstanding the importance of these experimental investigations, none of
them was directly aimed at resolving the rare-earth crisis, and the septuplet of
elements (Er, Yt, In, Ce, La, Di, and Th) remained outside the system. This does not
imply however that Mendeleev wasn

t pondering the issue. As will be argued in the
following paragraphs, Mendeleev had been working ardently on the problem from
a theoretical/philosophical line of approach, and there is much to be learned about
the crux of the rare-earth crisis from a careful and meticulous examination of
Mendeleev

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s trilogy of papers.

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12

Mendeleev, D. I. “On the Correlation between the Properties of the Elements and Their Atomic
Weights.” Zhurnal Russkogo Khimicheskogo Obshchestva 1, no. 2-3 (1869b): 35, 60-77. A
reproduction of Mendeleev s table appeared in Mendeleev, D. I. “Versuch Eines Systems Der

Elemente Nach Ihren Atomgewichten Und Chemischen Funktionen.” Journal f

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ur praktische €

Chemie 106 (1869c): 251. A more complete abstract of Mendeleev s article can be found in

Mendeleev, D. I. “ ¨ ber Die Beziehungen Der Eigenschaften Zu Den Atomgewichten Der
Elemente.” Zeitschrift f

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s supplementary
comments, made in autumn 1869, in Mendeleev, D. I. “On the Correlation between the Properties
of the Elements and Their Atomic Weights.” Zhurnal Russkogo Khimicheskogo Obshchestva
1 (1869f): 229-230, and an abstract in Mendeleev, D. I. “Die Beziehungen Zwischen Den
Eigenschaften Der Elemente Und Ihrer Atomgewichten.” Berichte der Deutschen chemischen
Gesellschaft 2 (1869g): 553.
13 Mendeleev, D. I. “Concerning the Atomic Volumes of Simple Bodies.” In Arb. II Kongr. Russ.
Arzt. Naturf ., 1869e.
14 Mendeleev, D. I. “On the Quantity of Oxygen in Metal Oxides and on the Valency of the
Elements.” Zhurnal Russkogo Khimicheskogo Obshchestva 2 (1870a): 14-21.

ur Chemie 5 (1869d): 405-406. See also Mendeleev €

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