94 FKAGMENTS OF SCIENCE. 



our researches. But it is not the less true that in the 

 case of wearing apparel and this for reasons which I 

 have given in analysing the experiment of Franklin 

 black dresses are more potent than white ones as ab- 

 sorbers of solar heat. 



Thus, in brief outline, have been brought before 

 you a few of the results of recent enquiry. If you ask 

 me what is the use of them, I can hardly answer you, 

 unless you define the term use. If you meant to ask 

 whether those dark rays which clear away the Alpine 

 snows, will ever be applied to the roasting of turkeys, 

 or the driving of steam-engines while affirming their 

 power to do both, I would frankly confess that they 

 are not at present capable of competing profitably with 

 coal in these particulars. Still they may have great 

 uses unknown to me; and when our coal-fields are 

 exhausted, it is possible that a more ethereal race 

 than we are may cook their victuals, and perform their 

 work, in this transcendental way. But is it necessary 

 that the student of science should have his labours 

 tested by their possible practical applications ? What 

 is the practical value of Homer's Iliad ? You smile, 

 and possibly think that Homer's Iliad is good as a 

 means of culture. There's the rub. The people who 

 demand of science practical uses, forget, or do not 

 know, that it also is great as a means of culture that 

 the knowledge of this wonderful universe is a thing 

 profitable in itself, and requiring no practical applica- 

 tion to justify its pursuit. 



But while the student of Nature distinctly refuses 

 to have his labours judged by their practical issues, 

 unless the term practical be made to include mental 

 as well as material good, he knows full well that the 

 greatest practical triumphs have been episodes in the 

 search after pure natural truth. The electric telegraph 



