INDEX. 



469 



Cretaceous and Jurassic periods, on 

 the limits of the, 321. 



Criticoids, on, 201. 



Croll (J.) on ocean-currents, 81, 180. 



Currents, on secondary, 52. 



Curves, on the mechanical description 

 of, 304. 



Davis (A. S.) on a theory of nebulae 

 and comets, 401. 



De la Rive (Prof. A.) on the organic 

 dust of the air, 229. 



Desains (P.) on solar radiation, 315. 



Dewar (J.) on the atomic volume of 

 solid substances, 339 ; on inverted 

 sugar, 345. 



Douglas's optometer, remarks on, 9. 



Draper (Prof. J. C.) on an improve- 

 ment in filtration, 335. 



Duppa (B. F.) on the action of so- 

 dium and iodide of ethyle upon 

 acetic ether, 309. 



Ear, on the structure of the human, 

 248. 



Earth, on the determination of the 

 absolute horizontal intensity of the 

 magnetism of the, 114; on the 

 course of geodesic lines on the sur- 

 face of the, 352. 



Eclipse, total, of Aug. 7, 1869, obser- 

 vations of the corona during the, 17. 



Ekman (Prof. F. L.) on the con- 

 nexion between the electrical insu- 

 lating-power and chemical compo- 

 sition of various kinds of glass, 

 437. 



Electrical dust-figures, on a new kind 

 of, 392. 



Electromagnetic experiment, on an, 

 428. 



Elements, on the refraction-equiva- 

 lents of the, 231. 



Elvanites of Knockmahon, on the 

 composition of the, 12. 



Eye, on the structure of the, 10. 



Felsites of Knockmahon, on the com- 

 position ot the, 12. 



Felspars, on the atomic constitution 

 of the, 348. 



Filtration, on an improvement in, 335. 



Flame-temperatures, investigation of, 

 in their relations to composition 

 and luminosity, 290, 337. 



Fluoride of silver, on the preparation, 

 composition, and physical proper- 

 ties of, 374. 



Frankland (Prof. E.) on the action of 



sodium and iodide of ethyle upon 

 acetic ether, 309. 



Garbett (E. L.) on popular difficulties 

 in tide theory, 174. 



Gas, on the variation of temperature 

 in a perfect, during expansion and 

 contraction, 288. 



Gas- analyses, on a simple method of 

 dispensing with observations of tem- 

 perature and pressure in, 465. 



Gases, on the expansion of, 127 ; on 

 the mechanical theory of, 317; on 

 the theory of the variation of tem- 

 perature in, 347 ; on the spectra of 

 some, under high pressures, 365. 



Geodesic lines, on the course of, on 

 the earth's surface, 352. 



Geological Society, proceedings of 

 the, 313, 383, 462. 



Gibbs (Dr. W.) on a simple method 

 of dispensing with observations of 

 temperature and pressure in gas- 

 analyses, 465. 



Gill (R.) on a possible cause of the 

 Gulf-stream, 238. 



Glaciers, on the veined structure of 

 the ice of, 241. 



Gladstone (Dr. J. H.) on the refrac- 

 tion-equivalents of the elements, 

 231. 



Glass, on the connexion between the 

 electrical insulating-power and che- 

 mical composition of various kinds 

 of, 437. 



Goodricke's theory of algol, on, 363. 



Gore (G.) on fluoride of silver, 374. 



Gulf-stream, on the influence of the, 

 on the climate of the arctic regions, 

 97 ; on a possible cause of the,238. 



Guthrie (Prof. Francis) on V ^1,282. 



Guthrie (Prof. Frederick) on approach 

 caused by vibration, 309. 



Harrison (J. P.) on solar radiation in 

 connexion with cloud and vapour, 

 70, 299. 



Heat, on the passage of radiant, 

 through ice, 8 ; on ocean-currents 

 in relation to the distribution of, 

 over the globe, 81 ; on the polari- 

 zation of, 280; on the diather- 

 mancy of a series of substances for 

 obscure, 396 ; on the change in the 

 radiation of, by roughness of the 

 surface, 445. 



Heath (Rev. J. M.) on the circum- 

 stances which determine the varia- 



