viii., May, 1874), pp. 288, 289.

Playpair, John. See vol. iii., pp. 131, 165.

Ill.u.s.trations of the Huttonian Theory, 1802.

Scrope, G. Poulett. See vol. iii., p. 132.

Consideration of Volcanoes, London, 1823, pp. 228-234.

Wells, W. C. See vol. iii., p. 185. Essay on Dew, London, 1818.

IV.--MODERN PHYSICAL AND CHEMICAL SCIENCES

Black, Joseph. See vol. iv., p. 12.

De acido e cibis orlo, et de magnesia, reprinted at Edinburgh, 1854. In this he sketched his discovery of carbonic acid. Later this paper was incorporated in his Experiments on Magnesia, Quicklime, and Other Alkaltne Substances.

Bunsen, William. See vol. iv., p. 69.

Cavendish, Henry. See vol. iv., p. 15.

"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 procedes du daguerreotype 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'Academie Royale des Sciences, between 1733 and 1737, contains Dufay's princ.i.p.al 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, ent.i.tled "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.

Memoire 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 a.s.sociation for the Advancement of Science, 1843, vol. xii" p. 33-

Kirwan, R. See vol. iv., p. 3 ff.

An Essay on Phlogiston and the Const.i.tution 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.

Kleist, Dean von. See vol. ii., p. 280.

In the Danzick Memoirs, vol. i. contains the description given by Von Kleist of his discovery of the Leyden jar. A translation is given also in Priestley's History of Electricity.

Lavoisier, Antoine Laurent. See vol. iv., p. 33.

Traite elementaire de chimie, Paris, 1774, trans, as Elements of Chemistry, by Robert Kerr, London and Edinburgh, 1790. Lister, Joseph Jackson. See vol. iv., p. 113.

On Some Properties in Achromatic Object Gla.s.ses Applicable to the Improvement of the Microscope, in Phil. Trans, for 1830.

Maxwell, James Clerk-. See vol. iii., p. 45.

" On the Motions and Collisions of Perfectly Elastic Spheres " in Philosophical Magazine for January and July, i860. The Scientific Papers of J. Clerk-Maxwell, edited by W. D. Nevin (2 vols.), vol. i., pp.

372-374, Cambridge, 1896. This is a reprint of Maxwell's prize paper of 1859. Mayer, Dr. Julius Robert. See vol. iii., p. 259.

The Forces of Inorganic Nature, 1842. This is Mayer's statement of the conservation of energy. Mendeleepp, Dmitri Ivanovitch. See vol. iv., p.