620 



INDEX. 



CUM 



Cumming's discoveries in thermo- 

 electricity, 545 



Cunaeus's discovery of the Leyden 

 jar, 234, 480 



Curves, discovery by the method 

 of, 610-611 



Cuthbertson's invention of ' guard- 

 ed gold points,' 481 



Cuvier's discoveries respecting 

 animal structures, 580, 602-603 



pleasure in making a discovery, 

 10 



DALE'S, K.W., statements re- 

 specting the nature of voli- 

 tion, 101, 123, 127-133 



D'Alibard's invention of the light- 

 ning rod, 480 



Dalton's chemical theories, 502, 

 508, 580, 598-599 



Daniell's invention of the con- 

 stant voltaic battery, 485 



Darwin's biological theories, 181, 

 580, 603-604 



Data, errors of, 115 



necessity of correct, 86 

 Davy's (Sir H.) discoveries of the 



alkali metals, 11, 181, 229, 483- 

 484, 522, 561 



530, 536, 542, 551, 557, 



561, 590-591 



experiments on the electro- 

 lysis of water, 355-358, 432-433 



excitement on discovering 



potassium, 11 



invention of the safety- 

 lamp, 530, 531 



Decomposability of electricity and 

 magnetism, hypothesis of, 520- 

 521 



Decomposition of water by elec- 

 tricity, discovery of, 481, 535- 

 537, 546-547, 554 



Deduction and Induction, 346 



discovery by means of, 460- 



461, 583, 584 



Deductive andj inductive action 

 of causes, 415 



Definite proportions, doctrine of, 

 475 



DIF 



Definitions, 74 



Definition, conditions of a good, 75 



of science, 2 



of scientific genius, 242-243, 

 252 



of the human will, 127, 605 



of the reasoning process, 332 



of the power of imagination, 

 360 



De la Hue's discoveries, 485, 561 

 De Luc's discoveries respecting 



temperatures, 566 

 Density of the earth, error in re- 

 searches on the, 107 

 Dependence of discovery upon art, 



187-188 



Descartes' discoveries, 478, 589 

 Detection of occult causes, 125- 

 126 



of minute objects, 323 



of similarities and differences, 

 328-329 



of individual substances, 393- 

 394 



of concurrent effects, 431 



of residual causes, 431-432 



of inseparable coincidences, 

 446 



of different crystalline sub- 

 stances by difference of angles, 

 598 



Determination of causes, 418-435 



of effects, 430 

 Determining causes, 411. 412 



conditions of phenomena, 439 

 Diamagnetism, discovery of, 494, 



561-562 



discovery of polarity of, 511 

 Diamond, discovery of the com- 

 bustibility of, 541 



Diathermancy of aqueous vapour, 

 discovery respecting the, 544 



of gases and vapours, discovery 

 of the, 544, 548, 574 



Melloni's discoveries in, 548,574 

 Differentiation of effects, 415 



of phenomena, 165 

 Difficulties of scientific research, 



11, 189, 209, 210, 211-212, 215- 

 216, 217-218, 372, 449 



