646 



INLEX. 



TRU 



Truth, gratification of the love of, 

 as a motive to research, 289-299 



the basis of intellect, 45 



undiscovered, darkness of, 214- 

 215 



Truths, fundamental, of science, 



159 

 - obscurity of important, 25, 559 



value of new, 190-191 



not created by reasoning, 340 

 341 



undiscovered, 25 



Tubes, transmission of sound 

 through, 527 



Tycho-Brahe's discoveries in as- 

 tronomy, 573 



Tyndall's discoveries, 479, 511, 648 



TTLTIMATE CAUSE, the idea of 

 U an, 49-50, 403, 404, 409-410 



scientific ideas, 49, 409 



' Unconscious cerebration,' 70 

 Undulatory theory of light, dis- 

 coveries made by means of the, 

 590 



discovery of the, 590 



Unequal action of causes, 165-166 

 refrangibility of light, disco- 

 very of the, 478, 517-518, 527 

 Unexpected discoveries, 233-238 

 Unexplained phenomena, 195, 497 

 Unity in diversity, as a bond of 

 memory, 112-113 



of general plan in all animals, 

 580, 603 



Universal causation, the principle 



of, 160 

 consistency of truth, 153 



ether, discovery of the theory 

 of an, 589 



existence of matter and energy, 

 162 



Universality of law, 121, 123, 404 



of magnetism, 494, 511, 538, 

 549, 561-562, 585 



of motion, principle of, 162 

 Universities, deficiency of scien- 

 tific enquiry at our old, 284 



VIB 



Unproved hypotheses as a source 



of error, 119, 123, 134 

 Unpublished experiments, 221,236 

 Unsuccessful experiments, causes 



of, 459 

 Unsuspected circumstances as a 



source of error, 138-139 

 Uranus, discovery of the planet, 



476 

 Useless objects of search, 20 



TTACCINATION, origin of, 495 

 V Valves in human veins, dis- 

 covery of, 571 



Vanadium, Koscoe's discoveries 

 respecting, 505 



Vapours and gases are the pro- 

 ducts of volatile liquids, disco- 

 very that, 559 



Variation of atmospheric pressure, 

 discovery of, 525-526 



of the force of gravity with al- 

 titude, discovery of the, 586 



of the magnetic needle, disco- 

 very of the, 518, 569-570 



is not uniform, dis- 

 covery that the, 570 



Vastness of future discovery, 7, 22, 

 26-28, 394, 469, 563 



Vauquelin's discoveries, 504 



Venus, discovery of the phases of, 

 475 



Velocity of an electric current, 

 discovery of the, 511, 533 



of light, discovery of the, 548, 

 587-589 



Fizeau's determination 



of, 548 

 and of gravity, 31 



of shot, discovery of the, 475 



of sound, 474-475, 491 

 Velocity produced by the explo- 

 sion of a planet, 610 



Vesta, discovery of the planet, 



509-510 

 Vibrations, experiments on, 475 



discovery respecting harmonic, 

 565 



of electrolytic, 238, 518-519 



