"Experiments on Air," in Phil. Trans., 1784, p. 119. This paper contains Cavendish's discovery of the composition of water and of nitric acid. Daguerre, Louis J. M. See vol. iv., p. 70. Historique et description des procédés du daguerréotype et du diorama, Paris, 1839. (This was translated into English.) Dalton, John. See vol. iv., p. 40. "On the Absorption of Gases by Water," read before the Literary and Philosophical Society of Manchester, October 21, 1803. This was published in 1805, and contains the atomic weight of twenty-one substances, some of which were probably added, or corrected, between the date of the first reading and the publication. Davy, Sir Humphry. See vol. iv., pp. 48, 209. "Some Chemical Agencies of Electricity," in Phil. Trans, for 1806, vol. viii. Researches, Chemical and Philosophical, chiefly concerning Nitrous Oxide or De-phlogisticated Nitrous Air and its Respiration, London, 1800. Dewar, James. See vol. v., p. 39. "Solid Hydrogen," in Proc. Roy. Inst, for 1900. "The Nadir of Temperature and Allied Problems " (Bakerian Lecture), Proc. Roy. Soc, 1901. Dufay, Cisternay. See vol. ii., p. 267. Histoire de l'Académie Royale des Sciences, between 1733 and 1737, contains Dufay's principal papers. Eulbr, Leonard (1707-1783). See vol. iii., p. 17. Lettres a une Princesse d'Allemagne sur quelques sujets de physique et de philosophie, St. Petersburg, 1768. Faraday, Michael. See vol. iii., p. 241. On the Induction of Electric Currents, in Phil. Trans. of Royal Society for 1832, pp. 126-128. Explication of Arago's Magnetic Phenomena, by Michael Faraday, F.R.S., Phil. Trans, of Royal Society for 1832, pp. 146-149. Franklin, Benjamin. See vol. ii., p. 286. New Experiments and Observations on Electricity, London, 1760. Galvani, Luigi (1737-1798). See vol. iii., p. 229. De viribus electricitatis in motu musculari commentatio, Bologna, 1791. This discovery of Galvani was first brought to notice by Volta's famous paper to the Royal Society, entitled "An Account of some Discoveries made by Mr. Galvani, of Bologna," published in the Phil. Trans, for 1793, pp. 10-44. Gay-Lussac, Joseph Louis. See vol. iv., p. 41. Mémoire sur la combinaison des substances gazeuses, Mem. Soc. d'Arcueil, 1809. Halley, Edmund. See vol. iii., p. 7. An Account of Several Extraordinary Meteors or Lights in the Sky, in Phil. Trans., vol. xxix., pp. 159-162, London, 1714. Helmholtz, H. L. F. See vol. iii., p. 280. Handbuch der physiologische Optik, Leipzig, 1867. Joule, J. P. See vol. iii., p. 269. On the Calorific Effects of Magneto-Electricity and the Mechanical Value of Heat, in Report of the British Association for the Advancement of Science, 1843, vol. xii" p. 33- Kirwan, R. See vol. iv., p. 3 ff. An Essay on Phlogiston and the Constitution of Acids, London, 1789. This is interesting, written as it was just before Lavoisier's Elements treated the same subject from the stand-point of the anti-phlogistic chemists.