514 SPECIAL METHODS OF DISCOVERY. 





not impossible that relations between electricity and light 

 also exist, and researches for the purpose of discovering 

 them are highly worthy of being made. The relation 

 between gravity and the physical forces, which Faraday 

 believed to exist, remains yet to be found ; and, for aught 

 we know, lines of electric force, like light and radiant 

 heat, may be decomposable ; but no experiments have yet 

 been made which prove it. 



The hypothesis of the existence of fluorine is a well- 

 known one, and many attempts to isolate that element 

 have been made by different chemists. I have made a 

 great many experiments with this object, some of which, 

 it might have been supposed, could not possibly fail ; but 

 although a large amount of new knowledge has been 

 obtained respecting many of the fluorides, none of the 

 experiments have been successful in isolating fluorine. 



It has been remarked that true hypotheses are not 

 essential to discovery ; and this is correct, because new 

 discoveries are sometimes made whilst endeavouring to 

 establish false or defective suppositions. A discoverer 

 may, in nearly all cases, be compared to a traveller in a 

 new country ; and if he should travel along a new road, 

 notwithstanding it may be a wrong one, he can hardly fail 

 to perceive new scenery. Exceptions to the usual prin- 

 ciple that true hypotheses are necessary to research, are 

 explained by and included in the still wider principle, 

 that every new combination of matter and its forces 

 must produce new effects ; and whether the theory or idea 

 which gives rise to an experiment be true or false, this 

 canon holds good. This also explains the fact, that occa- 

 sionally persons who imagine and execute new experiments, 

 but who are less fully acquainted with the details of 

 the sciences than are many scholastic scientific teachers, 

 succeed in making discoveries. It was well known that 



