Footnote 10: _Mineral Industry_, 1917, =26=. Footnote 11: _Review of Foreign Press, Technical Supplement_, War Office, May 27, 1919, p. 395. Footnote 12: _Mining Journ._, Dec. 27, 1919. Footnote 13: _Chem. and Met. Eng._, Oct. 15, 1918, p. 607. Footnote 14: Hill, Jas. M.: “Platinum Deposits of the World,” _Eng. Min. Journ._, June 30, 1917. Footnote 15: Merz, A. R.: _Journ. Ind. and Eng. Chem._, Nov. 1918, =10=, No. 11. Footnote 16: _Annual Statements of Trade of the United Kingdom._ Footnote 17: Spurr, J. E.: “Who Owns the Earth?” _Eng. Min. Journ._, Feb. 7, 1920. Footnote 18: _Records Geol. Surv. of India_, 1916, =47=, pt. 3, p. 163. Footnote 19: _Records Geol. Surv. of India_, 1919, =50=, pt. 3, p. 156. Footnote 20: _Records Geol. Surv. of India_, 1915, =46=, p. 284. Footnote 21: Zealley, A. E. V.: _South Rhod. Geol. Surv., Short Rept._ No. 3, March 20, 1918. Footnote 22: _Bull. Imp. Inst._, 1907, =5=, p. 137. Footnote 23: “Geology of the Selukwe Mineral Belt,” _Geol. Surv. Bull. South Rhod._, 1919, No. 3, p. 65. Footnote 24: Versfield, W.: Rept. on Metal Resources of Union of S. Africa, 1918. Footnote 25: Goodchild, W. H.: _Trans. Inst. Min. and Met._, 1916–17, =26=. Footnote 26: Bettel, W.: _S. African Mines_, Nov. 10, 1916. Footnote 27: Hall, A., and Humphrey, W. A.: “The Chromite Deposits of the Bushveld Plutonic Complex,” _Trans. Geol. Soc. S. Africa_, 1908, =11=, pp. 75–6. Footnote 28: _Mining Journ._, Feb. 29, 1913. Footnote 29: Mackenzie, G. C.: _Can. Min. Inst. Bull._, April 1919. Footnote 30: Camsell, C.: _Mining Journ._, May 1914, p. 523. Footnote 31: Uglow, W. L.: “Geology of Platinum Deposits,” _Eng. Min. Journ._, Aug. 30, 1919; Sept. 6, 1919. Footnote 32: _Chem. Trade Journ._, 1911, =49=, p. 271. Footnote 33: _Min. Sci. Press_, April 10, 1920, p. 536. Footnote 34: _Board of Trade Journ._, 1917, =99=, p. 156. Footnote 35: _Can. Min. Journ._, 1916, =37=, p. 548. Footnote 36: _Can. Min. Inst. Bull._, 1918, No. 63, p. 99. Footnote 37: _Geol. Surv. of Canada, Min. Res. of Canada_, 1903, No. 818. Footnote 38: _Board of Trade Journ._, April 17, 1919, p. 504. Footnote 39: Howley, G. P.: _Mining World_, 1907, =26=, p. 783. Footnote 40: _N.S.W. Dept. of Mines, Ann. Rept. for 1918_, p. 52. Footnote 41: _N.S.W. Dept. of Mines, Ann. Rept. for 1915_, p. 59. Footnote 42: Hill, Jas. M.: “Platinum and Allied Metals in 1916,” _U.S. Geol. Surv._, July 12, 1917. Footnote 43: _Rec. of Geol. Surv. N.S.W._, 1916, =9=, pt. 3, p. 127. Footnote 44: _Min. and Sci. Press_, April 10, 1919. Footnote 45: Bell, G. M.: _Economic Geology_, 1906, =1=, No. 8, p. 749. Footnote 46: _Mineral Industry_, 1914, =23=. Footnote 47: Krusch, P.: “The Platinum Deposits of Germany’s Palæozoic” (trans. by F. S. Schmidt), _Min. and Sci. Press_, 1914, =109=, p. 880. Footnote 48: