1 The most important source for the study of is, of course, his own writings. These include: The Scientific Basis of Prohibition; shall alcoholic liquors as common beverages be commercially outlawed? (London, 1846); A ClassBook of Chemistry in which the Principles of the Science are Familiarly Explained and Applied to the Arts, Agriculture, Physiology, Dietetics, Ventilation, and the Most Important Phenomena of Nature (New York, 1851); Alcohol and the Constitution of Man (New York, 1854); Chemical Atlas; or, The Chemistry of familiar objects (New York, 1855); Chemical Chart (New York, 1855); The Handbook of Household Science (New York, 1857); Masquerade of the Elements in Lectures of the American Institute of Instruction (New York, 1860); The Correlation and Conservation of Forces (ed., New York, 1864); The Culture Demanded by Modern Life; A Series of Addresses and Arguments on the Claims of Scientific Education (ed., New York, 1867); Exposition of the Development Hypothesis (New York, 1871); Spencer and the Doctrine of Evolution, in Outline of the Evolution-Philosophy by M. E. Cazelles (New York, 1875); Herbert Spencer on the Americans and the Americans on Herbert Spencer (New York, 1883). Especially important are the reviews and editorials he contributed to his own magazine, The Popular Science Monthly (New York, 1872-1887), hereafter cited as PSM. John Fiske's Livingston Interpreter of Science for the People (New York, 1894), though uncritical and diffuse, is an interesting biography by a contemporary, and is a storehouse of material about Youmans. J. Fiske, Edward Livingston Youmans: The Man and his Work, PSM (May, 1890), is a good brief account. His A Century of Science and Other Essays (Boston and New York, 1900), and Darwinism and Other Essays (Boston and New York, 1886), also contain pertinent information about Youmans. The Letters of John Fiske, edited by Ethel Fisk (New York, 1940), include only stray references to Youmans; J. S. Clark, Life and Letters of John Fiske (Boston, 1917), on the other hand, contains much interesting material. The obituaries by Eliza Sketch of E. L. Youmans, PSM (March, 1887); by Grant Allen, Professor Youmans, London Academy (January 29, 1887); and in the New York Tribune (January 19, 1887), are all helpful. H. G. Good, Edward Livingston A National Teacher of Scientific Monthly (March, 1924), and his Edward Livingston Youmans in the Dictionary of American Biography (New York, 1936), may also be consulted. Henry Holt, Garrulities of an Octogenarian Editor (Boston and New York, 1923), gives an interesting contemporary attitude towards Youmans. See also Evolution in Science, Philosophy, and Art (New York, 1891). For the relations of with the House of Appleton, see Brief Studies of General Book Publishiwg Firms of the United States (Urbana, III., 1931); J. C.