DISCOVERY BY COMPARING COLLECTIONS OF FACTS. 583 



e. By arranging a collection of facts in particular 

 orders, and comparing the orders. This method also 

 discloses general truths. By arranging all conductors of 

 electricity in the order of their degree of that property, 

 it was found that the most perfect metals were the most 

 perfect conductors. By comparing together the order 

 of the elements with regard to their conducting power for 

 heat and that for electricity, the important discovery was 

 made that the orders were alike for the two forms of 

 energy, and therefore the conclusion could be drawn that 

 the one phenomenon was related to the other in some 

 intimate way ; probably either as cause and effect, or as 

 concomitant effects of the same cause. By arranging also 

 all the elementary bodies in their order of degrees of 

 magnetic capacity, and in that of their number of atoms 

 in a given volume, it was discovered that their capacity 

 for magnetism increased with the increase of the number 

 of atoms. 



CHAPTER LVIII. 



DISCOVERY BY MEANS OF STUDY AND INFERENCE. 



No truth of great magnitude can be discovered without 

 the employment of inference. A new inference which 

 does not include more than the facts from which it is 

 drawn is a real discovery ; but so far as it extends beyond 

 them it is a mere hypothesis or theory, and only becomes 

 a discovery when the deficient evidence is supplied. An 

 inference is not a discovery until it is proved. The in- 

 ferences logically drawn from truths are themselves 

 truths, but those drawn from hypotheses are themselves 

 hypotheses, until they have been proved by experiment, 

 observation, or other evidence. The inferences may be 



