Ospina, T.: Paper read before second Pan-American Congr., Jan. 3, 1916. Footnote 84: White, R. W.: _Eng. and Min. Journ._, 1897, =63=, p. 189. Footnote 85: Castillo, J. C.: _Min. and Sci. Press_, 1909, =98=. Footnote 86: “Platinum-seeking in Colombia,” _The Times_, Nov. 26, 1912. Footnote 87: _Mining Journ._, Nov. 30, 1918, p. 700. Footnote 88: Millar and Singewald: _Mineral Deposits of South America_, New York, 1919, p. 405. Footnote 89: Kunz, George F.: “Platinum and Palladium in Brazil,” _Pan-American Bull._, April 1919, p. 408. Footnote 90: _U.S. Comm. Repts._, 1919, No. 21, p. 387. PRINTED BY HAZELL, WATSON AND VINEY, LD., LONDON AND AYLESBURY, ENGLAND. ------------------------------------------------------------------------ TRANSCRIBER’S NOTES 1. Footnote [90] (was 64) was unanchored. 2. P. 59, added missing title “WORLD MAP OF PLATINUM DEPOSITS.” 3. Silently corrected typographical errors and variations in spelling. 4. Archaic, non-standard, and uncertain spellings retained as printed. 5. Footnotes were re-indexed using numbers and collected together at the end of the last chapter. 6. Enclosed italics font in _underscores_. 7. Enclosed bold font in =equals=. 8. Subscripts are denoted by an underscore before a series of subscripted characters enclosed in curly braces, e.g. H_{2}O.