HUMBOLDT, Views of Nature, Bohn’s ed., London, 1850, p. 380. This allegory did not appear in the first edition of the Views of Nature. In the preface to the second edition the author gives the following account of its origin: “Schiller,” he says, “in remembrance of his youthful medical studies, loved to converse with me, during my long stay at Jena, on physiological subjects.” * * * “It was at this period that I wrote the little allegory on Vital Force, called The Rhodian Genius. The predilection which Schiller entertained for this piece, which he admitted into his periodical, _Die Horen_, gave me courage to introduce it here.” It was published in _Die Horen_ in 1795. Footnote 2: HUMBOLDT, _op. cit._, p. 386. In his _Aphorismi ex doctrina Physiologiæ chemicæ Plantarum_, appended to his _Flora Fribergensis subterranea_, published in 1793, Humboldt had said “Vim internam, quæ chymicæ affinitatis vincula resolvit, atque obstat, quominus elementa corporum libere conjungantur, vitalem vocamus.” “That internal force, which dissolves the bonds of chemical affinity, and prevents the elements of bodies from freely uniting, we call vital.” But in a note to the allegory above mentioned, added to the third edition of the Views of Nature in 1849, he says: “Reflection and prolonged study in the departments of physiology and chemistry have deeply shaken my earlier belief in peculiar so-called vital forces. In the year 1797, * * * I already declared that I by no means regarded the existence of these peculiar vital forces as established.” And again: “The difficulty of satisfactorily referring the vital phenomena of the organism to physical and chemical laws depends chiefly (and almost in the same manner as the prediction of meteorological processes in the atmosphere) on the complication of the phenomena, and on the great number of the simultaneously acting forces as well as the conditions of their activity.” Footnote 3: Compare HENRY BENCE JONES, Croonian Lectures on Matter and Force. London, 1868, John Churchill & Sons. Footnote 4: Ib., Preface, p. vi. Footnote 5: RANKINE, W. J. M., Philosophical Magazine, Feb., 1853. Also Edinburgh Philosophical Journal, July, 1855. Footnote 6: ARMSTRONG, Sir WM. In his address as President of the British Association for the Advancement of Science. Rep. Brit. Assoc., 1863, li. Footnote 7: GROVE, W. R., in 1842. Compare “Nature” i, 335, Jan. 27, 1870. Also Appleton’s Journal, iii, 324, Mch. 19, 1870. Footnote 8: Id., in Preface to The Correlation of Physical Forces, 4th ed. Reprinted in The Correlation and Conservation of Forces, edited by E. L. Youmans, p. 7. New York, 1865, D. Appleton & Co. Footnote 9: Id., ib., Am. ed., p. 33 et seq. Footnote 10: JOULE, J. P., Philosophical Transactions, 1850, p. 61. Footnote 11: See American Journal of Science, II, xxxvii, 296, 1864. Footnote 12: