Arthur Michael
1918 Journal of the American Chemical Society  
1674 .IRTHTK MICH.\EL. V. The effect of recrystallization on the purity of samples of the salt. VI. The relatire effect of drying and fusing samples of dichromate. NOTE. Scandium from a Brazilian Source (Preliminary Announcement) .--While working upon zirconium, the writer observed that certain hydroxides from residues from which the most strongly basic elements had been removed, and which consisted mainly of iron, aluminium and titanium, dissolved in hydrofluoric acid imperfectly owing to the
more » ... ectly owing to the formation of a gelatinous substance. Several grams of this were collected and boiled for some time with concd. sulfuric acid in a platinum dish. The cooled residue dissolved readily even in hot water. The sulfate solution gave a precipitate with oxalic acid, and the oxalate upon ignition gave a paIe yellowish oxide. The solution in hydrochloric acid showed no absorption spectrum. The dilute chloride solution was rapidly precipitated by boiling with sodium thiosulfate. Oxalic acid gave no precipitate when heated with the original hydroxides dissolved in hydrochloric acid. These reactions prove conclusively that the gelatinous precipitate first formed consisted mainly of scandium fluoride. The above residues were obtained from 3razilian zirconia. At the present time there may be a little delay before work upon a large number of varieties of zirconium minerals is undertaken. c. JAMES. D U R H A M [CONTRIBUTIOS FROM THE The densities of the acids do not differ very much, i. e., that of fumaric acid is I b 2 j and of maleic acid is 1.590 (Tanatar and Tchelebijeff, J . Russ. Cltern. SOC., 22, (1890)). The value for ethyl fumarate is 1.0496 and for the maleate is 1.065S, both a t 25 ' . With the increase in the size of the alkyls, in the replacement of nuclear and also of acidic hydrogen, the differences in the gravities decrease, which is in agreetileiit 1% ith theory. (1903)) considers it probable that pyrocinchonic anhydride goes partly over in solution to such a compound, which also is not unlikely, as the accumulation of alkyl groups about a carbon likewise favors its affinity for hydroxyl (Michael, J . prukt. Chem., [2] 60,423, footnote 4 (1899); 64, 108 (1902)). * This word is suggested in place of stereotransmutation. Michael, J. prukt. Chem., [2] 46, 209, 425 (1892). In his Lehrb. d. Stereochemie, 1904, p. 222, Werner makes the historically inaccurate statement that Anschuetz (Ann., 254, 174 (1889)) and Fittig (Ibid., 259, 30 (1890) ) first, then Skraup (Monatsh., 12, 107 (1891)) called attention to the impossibility of the Wislicenus transmutation explanation, which was based on the instability of addition products that in reality are stable, and then Michael ( J . prukt. Chem., (21 46, 209 (1892)) proved it experimentally in numerous cases. This inverted order of priority, which is frequently met in the literature, is due to the oversight of the above-mentioned chemists that in the writer's first criticism (Ibid., 38, P I (1888)) of the Wislicenus hypothesis, practically all the reasons advanced later by them against that chemist's interpretation are clearly stated, and given in proof of its untenability. Liebermann, Ber., 23, 2513 (1890); 28, 1444 (1895). Stewart, Slereochistry, 1907, p. 189. (1917). The writer believes that the relations disclosed in his investigations on this subject are not uncommon in reversible organic reactions. e THIS JOURNAL, 38, 654, footnote 4 (1910). a Wislicenus, Verh. saech. Gesell. zu. Lei$zig, 1 8~5 , p. 489. An investigation of this subject, with the use of different solvents and also with the products kept in solution, would be of great theoretical interest. 6 Many of the conclusions given by Werner in his Lehrbuch der Stereochemie (pp. 377-400) on this subject are untenable, as the different relations to structure shown in direct and catalytic esterification were not taken into consideration.
doi:10.1021/ja02244a009 fatcat:5bicldipvfbm7c4wq654qgsjui