Gallium occurrence

Argentite, natural occurrence of, 22 668 Argentium Sterling, 12 562 Argentothiosulfate complexes, 19 215 Argillaceous limestone, 15 26 Argillic alteration zones, gallium in,... 

Occurrence. Gallium ores are rare. It occurs in aluminium and zinc ores, for instance bauxite and zinc blende. 

Kuroda, Kazuo, The occurrence of gallium in the hot springs of Japan, ... 

This circular reviews the occurrence of 34 trace elements in coal and the occurrence and distribution of chlorine, phosphorus, titanium, and manganese, which are not considered rare in coal. Separate chapters are devoted to germanium, gallium, and uranium in coal. 

Jhe distribution of beryllium, boron, titanium, vanadium, chromium, cobalt, nickel, copper, zinc, gallium, germanium, tin, molybdenum, yttrium, and lanthanum in the principal coal-producing beds of the Interior Province has been studied by the U. S. Geological Survey. Data, methods of sampling, and analyses are discussed by Zubovic and others (II, 12). This chapter discusses the occurrence of 13 of these elements with respect to geological and geochemical environments of coal deposition and chemical properties of the elements. Zinc and tin are not included in this study because they were detected in only a few samples. 

According to Dzurus and Hennig 15) the free chlorine necessary for the occurrence of reaction between graphite and aluminum trichloride does not act catalytically, as Riidorff and Zeller first assumed, but is partly taken up in the lattice. Riidorff and Landel 61) found this to be true of the gallium trichloride-graphite compound also. For both compounds the ratio Me Cl is between 1 3.2 and 1 3.4 and the compounds therefore oxidize potassium iodide solution and cause iodine to separate. 

He also concluded that at such concentrations the ions in the vicinity of the electrode are exhausted by reduction and that the current intensity depends mostly on the number of metal ions transported into this space by diffusion. He also pointed out that the position of the wave on the potential axis is characteristic of the reduced species and can be used for qualitative analysis. From occurrence of waves at -0.4 and -0.6 V in solutions prepared from metallic zinc, it was possible to conclude the presence of two impurities, attributed tentatively to indium and gallium. M. Shikata at the same meeting reported (11) the possibility of carrying out the reduction at the D.M.E. in a nonaqueous system - in sodium ethoxide. In the following year the Japanese chemist reported also the first reduction of an organic compound, nitrobenzene (12,13). 

Let me try to rephrase the argument. We assume that the combination of a finite number of fundamental properties, via a combinatorial approach, leads to a discrete set of macroscopic physical possibilities. We also know empirically that the chemical elements occur in a discrete manner since there are no intermediate elements between, say, hydrogen and helium. Le Poidevin is thus claiming that his combinatorial approach can be taken as an explanation for the discreteness in the occurrence of elements and furthermore that it justifies the fact that Mendeleev regarded the yet undiscovered elements like gallium as being physical possibilities rather than merely logical ones. 

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