DIFFICULTIES IN SELECTING A SUBJECT OF RESEAECH. 375 



disguised form, and that his hypotheses therefore respect- 

 ing it are all wrong. 



Every investigator also soon rejects questions which 

 are beyond his powers. We are often much better able to 

 judge of the degree of importance of a proposed research 

 than of our ability to carry it out. Our ability to dis- 

 cover is, in most cases, inversely proportional to the 

 degree of intrinsic importance of the desired issue. Many 

 researches might easily be selected which we know before- 

 hand must yield positive, new, and distinct effects, but such 

 investigations are nearly always of a comparatively un- 

 important kind, because the results of them are generally 

 only additional instances of a similar class to some already 

 known ; for instance, most of our tables of constants might 

 be largely extended. It would be hardly possible to 

 suggest a research which would be certain to yield a per- 

 fectly anomalous phenomenon. Perhaps the most pro- 

 bable way to suggest a research which would be likely to 

 yield one -would be to assume an hypothesis that any sub- 

 stance which is known to behave in an anomalous manner 

 with regard to one force would also behave similarly with 

 regard to another force. 



The embarrassment of selection is usually caused partly 

 by a desire to obtain valuable discoveries at little trouble 

 and expense, and partly by our being so little able to pre- 

 dict successfully new important effects. We know so little 

 about what is termed the 'internal resistance' of sub- 

 stances, which is believed to determine largely the special 

 effects of different forces upon them, or of the molecular 

 structures and motions which form essential portions of 

 nearly all physical and chemical phenomena, that the 

 selection of a subject of research is, to some extent, in 

 many cases a 'leap in the dark.' Those experiments, 

 however, are usually rejected which appear extremely un- 



