Astronomy, cause of the slow progress of our knowledge of, 78. Theory and practical observations distinct in, 132. An extensive acquaintance with science and every branch of knowledge necessary to make a perfect observer in, 132. Five primary planets added to our system, 274. Positions, figures, and dimensions of all the planetary orbits now well known, 275. Atomic theory, 305. Advantage of, 306. Atomic weights of chemical elements, 306. Attraction, capillary, or capillarity, investigated by Laplace and Young, 234. Bacon, celebrated in England for his knowledge of science, 72. Benefits conferred on Natural Philosophy by him, 104. His Novum Organum, 105. His reform in philosophy proves the paramount importance of induction, 114. His prerogative of facts, 181. Illustrated by the fracture of a crystallized substance, 183. His collective instances, 184. Importance of, 185. His experiment on the weight of bodies, 186. Travelling instances of, frontier instances of, 188. His difference between liquids and aëriform fluids, 233. Bartolin, Erasmus, first discovers the phenomena exhibited by doubly refracting crystals, 254. Beccher, phlogistic doctrines of, 300. Bergmann, his advancement in crystallography, 239. Bernoulli, experiments of, in hydrodynamical science, 181. Biot, his hypothesis of a rotatory motion of the particles of light about their axes, 262. Black, Dr., his discovery of latent heat, 322. Bode, his curious law observed in the progression of the magnitudes of the several planetary orbits, 308. Bodies, natural constitution of, 221. Division of, into crystallized and uncrystallized, 242. Bones, dry, a magazine of nutriment, 65. Borda, his invention for subdivision, 128. Botany, general utility of, 345. Boyle, Robert, his enthusiasm in the pursuit of science, 115. His improvement on the air-pump, 230. Brain, hypothesis of its being an electric pile, 343. Bramah’s press, principle and utility of, 233. Brewster, Dr., his improvement on lenses for lighthouses, 56. His researches prove that the phenomena exhibited by polarized light, in its transmission through crystals, afford a certain indication of the most important points relating to the structure of crystals themselves, 263. Cabot, Sebastian, his discovery of the variation of the needle, 327. Cagnard, Baron de la Tour, utility of his experiments, 234. Causes and consequences directors of the will of man, 6. Causes, proximate, discovery of, called by Newton _veræ causæ_, 144. Celestial mechanics, 265. Chaldean records, 265.