Pages denoted by numerals of this kind (_287_) refer to biographical notes, chiefly by the editor. Numerals like 426 refer to books discussed by De Morgan, or to leading topics in the text. Numerals like 126 indicate minor references. Abbott, Justice, I, _181_. Abernethy, J., II, _219_. Aboriginal Britons, a poem, II, 270. Academy of Sciences, French, I, 163. Adair, J., I, _223_. Adam, M., I, _65_. Adams, J. C., I, _43_, 82, 385, 388; II, 131, 135, 140, 303. Ady, Joseph, II, 42, _42_. Agnew, H. C., I, 328. Agricola, J., I, 394. Agricultural Laborer's letter, II, 16. Agrippa, H. C., I, _48_, 48. Ainsworth, W. H., II, _132_. Airy, I, _85_, 88, 152, 242; II, 85, 140, 150, 303, 347. Alchemy, I, 125. Alfonso X (El Sabio), II, _269_. Alford, H., II, _221_. Alfred, King, Ballad of, II, 22. Algebra, I, 121. Algebraic symbols, I, 121. Almanac, I, 300; II, 147, 148, 207. (_See Easter._) Aloysius Lilius, I, 362. Alsted, J. H., II, _282_. Ameen Bey, II, 15. Amicable Society, I, 347. Ampere, I, 86. Amphisbaena serpent, I, 31. Anagrams, De Morgan, I, 138. Anaxagoras, II, _59_. Anghera, II, 60, _60_, 61, 279. Annuities, Fallacies of, I, 157. Antichrist, I, 130. Antimony, I, 125. Antinewtonism, I, 162. Antinomians, I, 394. Antiphon, II, _59_. Antonie, F., I, _126_, 126. Apollonius, I, 41, 107. Apparitions, II, 47. Arago, I, _243_, 390. Aratus, II, _167_. Arbuthnot, I, _133_, 134. Archer, H., II, 90. Archimedes, I, 5, 11, 42, 83, 107. Archytas, I, _53_. Argoli, I, _104_. Aristocrat, as a scientist, I, 131. Aristotle, I, 5, 331. Arnobius, II, _73_. Arson, P. J., II, _207_. Ashton, R., II, _99_. Astrology, I, 118, 127, 128, 350; II, 43. Astronomer's Drinking Song, I, 380. Astronomical Aphorisms, I, 398. Paradox, I, 394. Police Report, I, 390. Society. (_See Royal Astronomical Society._) Astronomy, Bailly's exaggerated view of, I, 166. Astunica, Didacas, I, 90. Athanasian Creed, I, 371. Atheists, Philosophical, I, 1. Atoms, II, 191. {376} Attraction, I, 136, 151, 155. Augustine, St., II, _23_. Aurora borealis, I, 134. Austen, Jane, I, 191. Auzout, A., II, _300_. Aviation, Early ideas of, II, 8.