From Current Literature

On the Question of the Discovery of Manganese Analogues (Elements 43 and 75)

M. Korsunsky. Leningrad.

The existence in nature of analogues of manganese was predicted already by Mendeleev, who in his system of the elements left two vacant places for them and called them eka-manganese and dvi-manganese. Since that time, repeated attempts have been made to discover these elements. Thus, Kern in 1877 announced his discovery, in platinum ore, of the element “devium,” which later proved to be a mixture of iridium and rhodium. In 1879 Guyard discovered “uralium,” Kurt in 1903 “ammarillium,” and French in 1911 “kanadium.” However, none of the discoveries listed above was confirmed.

In June 1925 a paper appeared by Noddack, Tacke, and Berg, in which the authors asserted that in certain minerals they had succeeded in establishing the presence of impurities of the 75th and 43rd elements, named by the authors “rhenium” and “masurium.” Among the minerals in which, in the authors’ opinion, impurities of manganese analogues were present were columbites and platinum ore. Noddack, Tacke, and Berg were the first to apply X-ray spectral analysis to the manganese analogues; this analysis established that in the spectrum of the substance obtained by enrichment of columbites there are lines belonging to the 75th and 43rd elements.

The work of Noddack, Tacke, and Berg aroused doubt, since the lines found by them could also be assigned to the spectra of tungsten, osmium, and thallium. The result obtained by them for platinum—on which no X-ray analysis had been performed—seemed all the more doubtful.

To resolve this question, at the Physico-Technical X-ray Institute in Leningrad, jointly with the Institute for the Study of Noble Metals, a most thorough X-ray analysis of crude platinum was carried out. As a result of the analysis it was established that in platinum ore there is no 75th element in quantities even five times smaller than Noddack, Tacke, and Berg had supposed. According to Noddack’s data, platinum ore contained an impurity of the 75th element in an amount of 0.01%, and of the 43rd—in an amount of 0.01%. According to the data we obtained, platinum ore contains no 75th element in quantities greater than 0.002%.

At the end of 1925 a paper appeared by Dolejšek and Heyrovský, who, by an electrolytic method, studying the deposition potentials of elements from their salts, established that in manganese salts from the firm Kahlbaum and Merck “pro analysi” there are impurities of the 75th element. The existence of the 75th element was also confirmed by them by the X-ray method. They obtained lines of the 75th element that agreed better with the theoretically calculated ones than those obtained by Berg.

At the beginning of 1926 a paper by Druce appeared, and then papers by Loring and Druce, in which they succeeded in finding impurities of the 75th element in manganese ores.

According to Loring, he succeeded in finding in some of the ores he studied not only the 75th, but also the 85th, 87th, and 93rd.

In the middle of 1926 there appeared the work of Prandtl, who repeated the work of Noddack, Tacke and Berg, Dolejsek, Heyrovsky, and Loring.

In repeating Noddack’s work, Prandtl was unable to detect the lines of the 75th element. Prandtl then turned to Noddack with a request that he send him samples in which, in Noddack’s opinion, the 75th element was present. Such a sample was sent to Prandtl, but in it too Prandtl was unable to establish the presence of the 75th element. Prandtl then sent his assistant Grimm to Noddack in Berlin in order to clarify on the spot the contradiction that had arisen. Upon Grimm’s return, the apparatus used by Berg in the radiographic investigation was set up. The experiment of Noddack, Tacke and Berg was then repeated down to the smallest details, but again the result obtained was negative.

Next Prandtl repeated the work of Loring and Druse, and again Prandtl was unable to establish the presence of the 75th element in manganese ores.

Then Prandtl repeated the work of Dolejsek and Heyrovsky. Prandtl was able to establish that the salts of Kalbaum (of postwar manufacture) contain impurities of Zn, W, and Co, which account for the jump in potential observed by Heyrovsky. X-ray analysis likewise gave no lines of the 75th element.

Thus the question of the occurrence in nature of analogues of manganese remains open even now.

Literature

Noddak, Taske and Berg: Naturwissenschaften 14, 167, 1926.

Dolejsek and J. Heyrovsky: Nature, 116, 782, 1925.

Druce. Chem. News, CXXX, No. 3420, 273, 1925.

Zvjagintzev, Korsunski, Seljakov: Journal of the Russian Physico-Chemical Society.

O. Zvjagintzev, M. Korsunski und N. Seljakow. Nature, p. 262, 1926.

Prandl. Zeitsch. für Angewandte Chemie, No. 36, p. 109, 1926.