740 
INDEX. 
Radiometer, construction of, 338 (see Crookes) ; nature of the force producing the motion of the, 715, 
725 (see Schuster, Reynolds). 
Rails, superior durability of steel over iron explained, 174. 
Residual charge of the Leyden jar, 489. 
Reynolds (0.). On Rolling-friction, 155. — The effect of heat and viscosity to cause friction, 173; 
conclusion, 173. 
On the Forces caused by the communication of Heat between a Surface and a Gas ; 
and on a new Photometer, 725. — New photometer, 732 ; conclusion, 733 ; appendix, 734. 
On the Refraction of Sound by the Atmosphere, 315. 
Romanes (G. J.). The Croonian Lecture. — Preliminary Observations on the Locomotor System of 
Medusse, 269. — Structure and movements of the Medusae, 269; fundamental observations, 272; 
stimulation, 280 ; section, 288 ; additional facts tending to prove the identity of the specialized 
marginal tissue of Medusae with nervous tissue in general, 295 ; general summary, 301 ; postscript, 
305 ; explanation of the plates, 313. 
Rotation of the Sun, period of the, as deduced from magnetic variations, 388. 
Rucker (A. W.) (see Thorpe). 
S. 
Schuster (A.). On the Nature of the Force producing the. Motion of a Body exposed to Rays of Heat 
and Light, 715. — Appendix, 720. 
Sea-water, expansion of, by heat, 405. 
Siemens (C. W.). On determining the depth of the Sea without the use of the Sounding-line, 671. — 
Addendum on an attraction-meter, 689. 
Skull, development of the, in the Batrachia, 601 (see Parker). 
Snakes, development and succession of the poison-fangs of, 377. 
Sound, refraction of, by the atmosphere, 315. 
Sounding at sea, instrument for superseding, 675 (see Siemens). 
Spontaneous generation , 27 (see Tyndall). 
Spottiswoode (W.). On Multiple Contact of Surfaces, 227. — Recapitulation of former methods and 
results, 228 ; general theory of multiple contact of quadrics with other surfaces, 235 ; conditions 
for the cases n—2>, 4, 5^6, 242; on points of four-, five-, six-pointic contact with a quadric 
surface, 247. 
Suhm (see Willemoes-Suhm). 
T. 
Teeth of Fishes, development of, 257 (see Tomes). 
Thomson (Sir W.) . Electrodynamic Qualities of Metals. Part VI. — Effects of Stress on Magnetization, 
693 (for abstract see p. 712). 
Thorpe (T. E.) and Rucker (A. W.). On the Expansion of Sea-water by Heat, 405. 
Thyroid gland, minute anatomy of, in the dog, 557. 
Tomes (C. S.). On the Development and Succession of the Poison-fangs of Snakes, 3 77. 
■ On the Development of the Teeth of Fishes ( Elasmobranchii and Teleostei), 257. 
Turner (W.). On the Placentation of the Lemurs, 569 (for contents see p. 569). 
