Index. 309 



Refracting glass, picture how represented behind a, i. 1.56. 



Refraction (or refrangibility) of the rays of light defined, i. 

 145 lecture on, 142 principle of explained, and illus- 

 trated, ib. its application to the construction of optical 

 glasses, 151. 



Repulsion, some bodies possess a power of, i. 20 this 

 principle exemplified by the magnet, 25 the principle 

 that reflects light from polished surfaces, 164. 



Resins, how obtained, ii. 221 chemical remarks on, 282. 



Reverberatory furnace, use of, ii. 122. 

 Right ascension explained, i. 267. 



Right sphere, what so called, i. 264 situation and ap- 

 pearance of the heavens to the inhabitants of a, 265. 

 Rust of metals explained, ii. 229. 



S. 



Safety lamp, use of Sir H. Davy's, ii. 50. 



Salt, what the basis of common, ii. 54. 



Salts, distinction with respect to the compound, ii. 43 

 rule that they do not act but in solution, illustrated, 

 Q8 lecture on, 126 definition of the term, ib. phae- 

 iiomena in the mixture of, with water, 128 separa- 

 tion of the salts afterwards by evaporation, 131 process 

 and theories of crystallization, 132 to 138 methods of 

 separating sa ! ts in solution, 138 account of the alkaline, 

 140 of the acids, 147 of the compound, 168 effects 

 of the acid upon metals, 233. 



Samiel, the, or mortifying wind, i. Ql. 



Sandarach, nature of, ii. 283. 



Sarcocoll, cheaaical remarks on, ii. 273. 



Satellites, account of those of Jupiter, Saturn, and the 

 Georgium Sidus, i. 325 to 328 eclipses of Jupiter's, 

 ii. 29. 



Saturation, what the point of, ii. 33 process of, explained, 

 ii. 89. 129. 



Saturn, particulars concerning the planet, 307- See also 

 290. 290. 304 account of its satellites, 325 to 327- 



Screw, principle of this mechanic power, and its mode of 

 acting, i. 244. 



Sea, the green colour of accounted for, i. 212 inquiries 

 concerning its supposed gradual diminution of, ii. 256, 

 257- 



Seasons, lecture on their vicissitudes, ii. 1. 



