296 Index. 



Conductors, metallic, fixed to buildings as a security 

 against lightning, i. 1 19 conductors of caloric, ii. 62, 

 03. 



Constellations, account of, i. 258. 



Convex mirrors, why objects are diminished by, i. 170 to 

 172. 



Copernican system of the universe, i. 254, 255. 



Copper, at what heat oxidizes, ii. 227 its chemical pro- 

 perties, ii. 249, 250. 



Cranes, principle of these instruments, i. 23Q. 



Crystals where found, ii. 1QO. 



Crystallization of salts, process and theories of, ii. 134. 137 

 to 139. 



D. 



Day, the astronomical and the civil, ii. 4. 13, 14. The 

 artificial day, 8, 9. 11. 



Declination explained, i. 267. 



Dew, nature of, i 95. 



Diamond. See Carbon. 



Diana's tree, method of performing this experiment, ii. 

 247. 



Digestion, meaning of the term in chemistry, ii. 100. 



Digits, explanation of this term, as used in speaking of 

 eclipses, ii. 2y. 



Dioptrics, definition of, i. 163. 



Distillation, process of, ii. 81 description of vessels used 

 for this process in its varieties, ii. 108 to 111. 



Distorted figures reduced to symmetry by a cylindrical or 

 a conical mirror, i. 176. 



Divining circles, explanation of the experiment of, i. 31. 



Drawing water : principle on which this effect is pro- 

 duced by a ship, and the proportion, i. 43. 



E. 



Earth, motion of the, i. 2 attraction of the, 15 opinions 

 of the ancient astronomers concerning it, 252 form of 

 its orbit, 272 some particulars respecting it, considered 

 as a planet, 290 to 294. 304 lecture on this subject, 329 

 its figure, and illustrations of this, ib. inclination of 



