11 Sodium 34 Selenium 57 Lanthanum 80 Mercury 12 Magnesium 35 Bromine 58 Cerium 81 Thallium 13 Aluminium 36 Krypton 59 Praseodymium 82 Lead 14 Silicon 37 Rubidium 60 Neodymium 83 Bismuth 15 Phosphorus 38 Strontium 61 —— 84 Polonium 16 Sulphur 39 Yttrium 62 Samarium 85 —— 17 Chlorine 40 Zirconium 63 Europium 86 Emanation 18 Argon 41 Niobium 64 Gadolinium 87 —— 19 Potassium 42 Molybdenum 65 Terbium 88 Radium 20 Calcium 43 —— 66 Dyprosium 89 Actinium 21 Scandium 44 Rhuthenium 67 Holmium 90 Thorium 22 Titanium 45 Rhodium 68 Erbium 91 Uranium X 23 Vanadium 46 Paladium 69 Thulium 92 Uranium FOOTNOTES: [1] Mem. of the Manchester Lit. and Phil. Soc., (1851; 2d series), 107; Phil. Mag. XIV (1857), 211. [2] Phil. Mag., XIX (1860; 4th series), 28. Clausius had discussed some of the relations of this quantity in 1858 (Pogg. Ann. CV [1858], 239), but Maxwell’s magnificent work on the viscosity of gases first made possible its evaluation. [3] I, 375-36. [4] See Werke, IV, 281. [5] Op. cit., p. 294. [6] Phil. Mag., XI (1881; 5th series), 384. [7] Wissenschaftliche Abhandlungen, III, 69. [8] Kelvin, “Contact Electricity and Electrolysis,” Nature, LVI (1897), 84. [9] Scientific Transactions of the Royal Dublin Society, IV (1891; 11th series), 563. [10] See particularly Rutherford’s presidential address at the recent Liverpool meeting of the British Association, Science, LVIII (1923), 213. [11] J. J. Thomson and E. Rutherford, Phil. Mag., XLII (1896), 392. [12] Phil. Mag., XLIV (1898), 422. [13] Proc. Camb. Phil. Soc., IX, 401. [14] Phil. Trans., A 195, p. 193. [15] Annale de Chimie et de Physique, XXVIII, 289. [16] Phil. Trans., A 193, p. 129. [17] Leonard B. Loeb, Proc. Nat. Acad., II (1916), 345, and Phys. Rev., 1917. [18] Wellish, Amer. Jour. of Science, XXXIX (1915), 583. [19] L. B. Loeb, Jour. Franklin Inst., CXCVII (1924), 45. [20] H. A. Erikson, Phys. Rev., XX (1922), 118. [21] H. B. Wahlin, ibid., p. 267. [22] Verb. der deutsch. phys. Ges., XI (1909), 146 and 276. [23] Proc. Roy. Soc., LXXX (1908), 207. [24] Fournier d’Albe, Life of Sir William Crookes, 1924. [25] Proc. Roy. Soc., XL (1890), 526. [26] Phil. Mag., XLIV (1897), 298. [27] W. Wien, Wied. Ann., LXV (1898), 440. [28] Rays of Positive Electricity. London: Longmans, 1913. [29] Proceedings, IX (1897), 244. [30] Phil. Mag., XXIX (1890; 5th series), 56. [31] Ibid., p. 292; Nature, XXXVI, 412. [32] Proc. Camb. Phil. Soc., IX (1897), 333. [33] Ibid., p. 345. [34] Phil. Mag., XLVI (1898), 528.