786 



INDEX. 



Variation, linear, elliptic, &c. , 474 ; 



method of, 439. 

 Variations, logical, 140 : periodic, 



447 ; combined, 450 ; integrated, 



452 ; simple proportional, 501. 

 Variety, of nature, 1 73 ; of nature 



and art, 190 ; higher orders of, 



192. 



Velocity, unit of, 321. 

 Venn, Rev. John, logical problem 



by, 90 ; on Boole, 155 ; his work 



on Logic of Chance, 394. 

 Venus, 449 ; transits of, 294. 

 Verses, Protean, 175. 

 Vibrations, law of, 295 ; principle 



of forced, 451 ; co-existence of 



small, 476. 

 Vital force, 523. 

 Voltaire on fossils, 661. 

 Vortices, theory of, 513, 5 1 ?. 

 Vulcan, supposed planet, 414. 



WALLIS, 124, 175. 



"Water, compressibility of, 338; 



properties of, 610. 

 Watt's parallel motion, 462. 

 Waves, 599, 635 ; nature of, 468 ; 



in canals, 535; earthquake, 297. 

 Weak arguments, effect of, 211. 

 Wells, on dew, 425. 

 Wenzel, on neutral salts, 295. 



Whately, disjunctive propositions, 

 69 ; probable arguments, 210. 



Wheatstone, cipher, 124; galva- 

 nometer, 286 ; revolving mirror, 

 299, 308 ; kaleidophone, 445 ; 

 velocity of electricity, 543. 



Whewell, on tides, 371, 542; me- 

 thod of least squares, 386. 



Whitworth, Sir Joseph, 304, 436. 



Whitworth, Rev. W. A., on Choice 

 and Chance, 395. 



Wilbraham, oil Boole, 206. 



Williamson, Professor A. W., che- 

 mical unit, S21 ; prediction by, 

 544. 



Wollaston, the goniometer, 287 ; 

 light of moon, 302 ; spectrum, 

 429. 



Wren, Sir C., on gravity, 581. 



X, THE substance, 523. 



YARD', standard, 397. 



Young, Dr. Thomas, tension of 

 aqueous vapour, 500 ; use of 

 hypotheses, 508 ; ethereal me- 

 dium, 515. 



ZERO point, 368. 

 Zodiacal light, 276. 

 Zoology, 666. 



CI.AY, SONS, AND TAYLOR, PRINTERS, 



