[31]. Humboldt, “Personal Narrative of Travels to the New Continent,” London, 1822, Vol. II, p. 273.
[32]. See p. 473.
[33]. Yriarte, “Autour des Borgia,” Paris, 1891, pp. 136, 137.
[34]. See Yriarte, “Venice,” Paris, 1878, p. 236.
[35]. Ibid., pp. 252, 253.
[36]. Guidius, “De Mineralibus,” Frankfort, 1627, p. 74.
[37]. Ibid., p. 73.
[38]. Ibid., pp. 75–77.
[39]. Croker, “Lord Hervey’s Memoirs,” London, 1848, Vol. I, pp. 88, 89.
[40]. “The Naturall Historie of C. Plinius Secundus,” London, 1601, Book IX, ch. 35.