INDEX. 



625 



ERR 



Erroneous hypotheses, as aids to- 

 wards truth, 123-124 



Error caused by assumption of oc- 

 cult causes, 124-133 



how to reduce its amount, 139 



in science, definition of, 105 



its frequent similarity to truth, 

 104 



unavoidable, 112 



prevalence of, 106, 110 



rarity of perfect freedom from, 

 141 



remarkable instance of, 109 



signs of, 137-139 



sources of, 109, 111, 113-139 

 Errors, constant ones, 139 



correction of, 139-140 

 Essential causes, 410 



oils, discovery of, 539-540 

 Ether, discovery of the theory of 



an universal, 589 

 Euler, the mathematician, 40 



scientific industry of, 252-253 

 Evidence, analysis of, 333 



conflicting, 351-352 



what is sufficient ? 99-100 

 Evolution of animals, theory of, 602 



of truth, its dependence upon 

 law, 182 



Exceptional cases, 85, 196-197, 



199, 386 

 discovery by investigation 



of, 199, 498-500 

 Exciting causes, 411, 412 



conditions of phenomena, 437- 

 438 



Experiment, an, how conducted, 

 311,317 



as a means of discovery, 307 



mode of observing an, 317 

 Experiments, causes of unsuccess- 

 ful, 382, 459 



converse, discovery by making, 

 549 



explanation of results of, 354 

 355 



haphazard, 426 



how planned, 308-311 



limits of, 213 



necessity of well-chosen, 385 



FAR 



Experiments, new, discovery by 

 means of, 525 



notes of, how taken, 317 



unpublished, 221, 236 

 Explaining results, difficulty of, 



449, 451 



Explanation of a phenomenon, 

 conditions of, 387 



of the results of experiments, 

 354-355 



Explanations, testing of, 451-452 

 Exploded comet, discovery of an, 



609 

 Explosion of a planet, velocity 



produced by the, 610 

 ' Explosive antimony,' discovery 



of, 238-239, 550, 567 

 ' Extension ' of meaning of terms, 



52, 78 

 Extreme instances, discovery of, 



200-201, 386 



TjWBRONI'S inference respecting 



J_ the chemical origin of the vol- 

 taic current, 592 



Fabricius's discovery of the spots 

 on the sun, 566 



Facts, generalised, 84 



Fahrenheit, improvement of ther- 

 mometer by, 479 



Failure in experiment, causes .of, 

 382, 459 



Fallacy in science, meaning of, 105 



Falling bodies, discovery of the 

 law of descent of, 487-488 



False belief, pleasures of, 95 



beliefs, source of, 103 



discoveries, 135-137 



statements, evil effects of, 86 

 Fame as a motive to research, 



289, 291 

 Faraday's loss of memory, 63 



scientific character, 242, 257 



discoveries, 226, 485, 493, 494, 

 509, 518, 522-523, 531, 537, '545, 

 548, 549, 551, 561-562, 585, 594 



invention of the voltameter, 568 



prediction of electric charge of 

 telegraph cables, 231 



S S 



