RELATIVE IMPORTANCE OF DISCOVERIES. 189 



CHAPTEE XIX. 



RELATIVE IMPORTANCE OF DIFFERENT RESEARCHES AND 

 DISCOVERIES. 



ONE of the commonest of mistakes and most injurious io 

 a sound scientific judgment is neglecting to value diffe- 

 rent truths according to their relative degrees of intrinsic 

 importance. It is, however, often very difficult to estimate 

 these degrees in pure science, because there is at present 

 no fixed standard of their value. 



Our conceptions of the phenomena of the universe 

 are continually trammelled by our personal relations to 

 them, and we find it difficult to consider them apart from 

 ourselves. Every scientific person, therefore, adopts a 

 different standard by which to value new truths, and 

 estimates them according to the relation they bear to 

 himself, his occupation, and his views of nature ; and 

 nearly all commercial persons value them only according 

 to the amount of immediate pecuniary benefit they confer 

 on the trading community. Most persons also consider 

 practical inventions to be of greater importance than 

 abstract discoveries ; but such discoveries often contain 

 fruitful truths from which many inventions spring ; as, 

 for instance, that of voltaic electricity, which gave rise to 

 electro-plating, and that of electro-magnetism which 

 yielded the electric telegraph. Less than fifty years ago no 

 extensive practical applications of electricity were known, 

 and electricity itself was considered to be only a philo- 

 sophical toy ; but now its great value in the telegraph and 

 in electro-plating is recognised by every civilised person. 

 The discoveries of gutta-percha, india-rubber, and many 



