^{page 535 note 1} Abhandlung der Grossherz. Hessisch. Geol. Lnades. zu Darmstadt, Band iv, Heft iii, Wm. Schottler.

^{page 535 note 2} 28th Bericht der Oberhessischen Gesell. für Natur- und Heilkunde.

^{page 535 note 3} “Die Brauneisenerzlagerstätten des Seen- und Ohmtals am Nordrand des Vogelsgebirges”: Zeitsch. Für Prak. Geol., 1905, p. 242.

^{page 535 note 4} “Sur les Bauxites de la Chaine des Alp.”: Bull. Soc. Géol. de France, tome xxviii (1871), p. 111.

^{page 535 note 5} “The Rhyolites of the County of Antrim”: Sci. Trans. Roy. Dub. Soc., 1896, ser. ii, vol. vi.Google Scholar

^{page 535 note 6} “Beiträge zur Geologie der Seyschellen”: Neues Jahr. für Min. Geol. und Palæontologie, 1898, p. 163.

^{page 535 note 7} “On the Constitution of Laterite”: Geol. Mag., 1903, Vol. X, p. 59.Google Scholar

^{page 535 note 8} “The Composition of Indian Laterite”: Geol. Mag., 1903, p. 154.

^{page 535 note 9} “On the Origin of certain Laterites”: Geol. Mag., 1906, Dec. V, Vol. III p. 536.Google Scholar

^{page 535 note 10} “East Africa Protectorate.”

^{page 535 note 11} “Data of Geochemistry”: xxxxxx Bulletin No. 330, U.S. Geol. Survey, 1908.

^{page 535 note 12} “Petrogenesis,” 1906.

^{page 536 note 1} der Grossherz, Abhandlung. Hessisch. Geol. Landes zu Darmstadt, Band iv, Heft iii, pp. 331, 451–67.Google Scholar

^{page 536 note 2} Op. cit., p. 244.

^{page 536 note 3} p. 243.

^{page 536 note 4} See paper by Tate, & Holden, , Quart. Journ. Geol. Soc, 1870, p. 155.Google Scholar

^{page 537 note 1} “Die Brauneisenerzlagertätten des Seen- und Ohmtals am Nordrand des Vogelsgebirges”: Zeitsch. für Prak. Geol., 1905, p. 251.

^{page 537 note 2} Op. cit., p. 72.

^{page 537 note 3} p. 75. Some beautiful points are indicated by Liebrich in this connection, viz., that the basalt-ironstone pieces, also met with in the bauxitic clay, have the same structure as the anamesite, and that the proportions of Fe₂ O₃ and Al₂ O₃ in the ironstone, and Al₂ O₃ and Fe₂ O₃ in the bauxite, correspond atomically—they alternate.

^{page 538 note 1} It interests me to find that Münster questions whether a tropical climate has been a factor in the formation of the Vogelsberg iron-ores and bauxites. Op. cit., p. 257.

^{page 538 note 2} Whether in Ireland or in Southern France in earlier geological times; or in India, the Deccan, Malabar, etc., to-day; Georgia, Alabama, Arkansas; Brazil, Surinam; the Congo, East Africa; the Seychelles, Java, Sumatra, and the Hawaiian Islands—all have their aluminous clays and ores; and so natural has it become to assume a hot climate that Bauer assumes it (Neues Jahrbueh, 1898, p. 219), a view mentioned without comment by Doelter (“Petrogenesis,” 1906, p. 235).

^{page 539 note 1} Geol. Mag., 1906, p. 546.

^{page 539 note 2} Some 9,500 feet. Op. cit., p. 42. If tropical heat were the determining condition, should we not expect lateritic deposits everywhere throughout the tropics, declining in importance northward and southward in the temperate zones, wherever basalts, dolerites, etc., appear at the surface? Münster, while questioning the existence of tropical conditions during the formation of the laterites at Mücka, resorts to thermal springs, with Chelius and Delkeskamp (op. cit., p. 257), as the effective cause. The carbonated waters of the springs, he believed, brought up iron and bore it into the laterite layer, as well as promoting the weathering of the basalt. As to this I would remark—

(1) Thelaterite layer, always superficial (practically), occurs from 1 to 3 kilometres from the fault along which the supposed springs issued. Could the waters have retained heat to such distances and have affected only a superficial layer of rock?

(2) Thepeculiar weathering has proceeded from above downward, the greatest concentration of iron-oxide being at the bottom. Is this not analogous to the case of iron-pans in soils on a larger scale?

(3) Theamount of iron given up by the basalt, in weathering to clay in the uppermost 20 feet, could easily account tor the aggregate of limonite deposited in the lower 20 feet.

(4) Maynot the C O2 given oft by springs, such as those now at Nauheim and along other lines of post-basalt dislocations, including that at Miicka, have been carried into the earth from the atmosphere, and affect the rock more generally than when issuing only at points here and there?

^{page 539 note 3} G. H. Kinahan relied upon the leaching action of the organic acids from decomposing peat to account for the formation of bauxite. Trans. Manch, . Geol. Soc., 1894, vol. xxii, p. 458Google Scholar. This is mentioned by Clarke, op. cit., p. 420.

^{page 540 note 1} Clarke, , “Data of Geochemistry,” p. 424.Google Scholar

^{page 540 note 2} Particularly if present in such strength as to produce intensive action (Geol. Mag., 1906, pp. 539–40).

^{page 540 note 3} “Petrogenesis,” p. 235.

^{page 540 note 4} Amongst the first to propose this was Professor Cole, G. A.; see “The Rhyolites of the County of Antrim,” p. 108Google Scholar. Clarke mentions the emanations from volcanoes, as in Java, Sumatra, and Hawaii, op. cit., p. 425. See also du Bois, G. C. and Bauer, , quoted by Doelter, “Petrogenesis,” p. 235Google Scholar; and Hayes, and Liebrich, , referred to by Clarke, p. 421.Google Scholar

^{page 541 note 1} Watts' Chem. Dict., vol. v, p. 1017.Google Scholar

^{page 541 note 2} Geol. Mag., 1906, pp. 539–40.

^{page 541 note 3} I have found compact basalts as highly transformed as were those which had manifestly zeolitie, and under similar circumstances.

^{page 542 note 1} Geol. Mag., pp. 539–40.

^{page 542 note 2} Zeitschr, . für Prak. Geol., 1905, p. 333Google Scholar. Paper by O. Stutzer in which he gives, with approval, Rösler's view.

^{page 542 note 3} Liebrich, , op. cit., p. 96Google Scholar. The author believes that Al₂ O₃ was dissolved out of the rothen Hang clay and concentrated in crevices, etc., of the bauxite lumps, as hydrargillite.