1877] WRITINGS OF JOSEPH HENRY. 517 



what known action of electricity sucii an effect could pos- 

 sibly be produced : for this purpose we invent an hypothe- 

 sis, or imagine some peculiar action of electricity sufficient to 

 produce the effect in question ; we then say to ourselves, if 

 this be true, it will logically follow that a specific result will 

 take place if we make a certain experiment; the experiment 

 is devised and tried, but no positive result is obtained. In 

 order to this negative result, the logical deductions must 

 have been inconclusive, or the experiment must have been 

 defective, or the hypothesis itself erroneous. 



We examine each of the two former steps, and finding 

 nothing amiss in them, we conclude that the hypothesis was 

 not true. Another hypothesis is then invented, another de- 

 duction inferred, and another experiment made ; still no re- 

 sult is obtained. At this stage of the research the inexpe- 

 rienced investigator is prone to abandon the pursuit: not 

 so he who has successfully attempted to penetrate the se- 

 crets of nature. Undeterred by failure, he changes from 

 time to time his h3''potheses, makes new guesses, and again 

 repeats the question as to their truth by means of experi- 

 ment; until at length nature — as if wearied by his solicita- 

 tions, grants him a new and positive result. He has now two 

 facts, and an hypothesis to explain them ; from this hypoth- 

 esis he makes a new deduction, which is also tested b}^ a 

 new experiment; but now perhaps he obtains a result which 

 although of a positive character, is not what he expected. 

 He has however made an advance ; he has three facts and 

 an hypothesis to explain two of them. In this case he does 

 not usually abandon his preconceived idea, but modifies it 

 until it includes the new fact. With the hypothesis thus 

 improved, he deduces — it may be in rapid succession, a num- 

 ber of new conclusions, the truth of all of which is borne out 

 by the results of the experiments. The investigator now 

 feels that he is on the right track; that the thread of Daeda- 

 lus is in his hand, and that he will soon be in the full light 

 of day : but usually the escape from the labyrinth is not so 

 easy. In the height of his successful career it not unfre- 

 quently happens that a result is obtained diametrically op- 



