302 Index. 



Iodine, an acidifying principle, ii. 54. 



Iron, attraction between, and the loadstone, i. 22 mag- 

 netic virtue, how acquired by, 30 expansion of cast, 

 in cooling, ii. 60. 



Jasper, nature of, i. 189, 1QO. 



Jelly procured from fruits, what, ii. 278. 



Juno, some particulars concerning this newly discovered 

 planet, i. 304. 306. 



Jupiter, particulars of the planet, i. 30?. See also 2QO. 

 2Q5. 304, 305 account of his satellites, 325. 328 

 their eclipses, ii. 29. 



Jupiter's satellites, velocity of light discovered by the 

 eclipses of, i. 130. 



K. 



Kite, Dr. Franklin's discovery and experiments with the 

 electrical, i. 114, 115. 



L. 



Lakes, reason why deep do not freeze in winter, ii. 64. 



Latitude, meaning of the term, i. 257. 



Laws of nature, explanation of the phrase, i. 6. 



Lead, when oxidized, ii. 228 chemical properties of, 252. 



Lens, definition of the term, i. 145 different sorts of 

 lenses, and their effects, 152. 160. 



Levers, three different sorts of, and their modes and power? 

 of action, i. 233. 236, 237. 



Leyden phial, the discovery and nature of the, i. 106 

 powerful shock given by the, 107 experiment with, 

 proving the force of the electrical matter, 1 12. 



Libration of the moon explained, i. 317. 



Light, lecture on, i. 12Q different opinions concerning its 

 nature, ib. its most remarkable properties, 130 its 

 astonishing velocity, ib. its inconceivable rarity, 133 

 its force or momentum ; curious experiment proving 

 this, 13Q its constant motion in straight lines, 141 

 general principles and definitions concerning light, 142 

 newly discovered property of, called polarization, 213. 

 See also Colours, Reflection, and Refraction. 



Lightning. See Thunder. 



Lime, chemical account of, considered as one of the 

 earths, ii. 191 to 195. 



