ATOMS AND MOLECULES 1 



IT is often a question with the scientific student as to 

 whether his investigation can lead to any real advancement of 

 knowledge, or whether the outcome will merely add to the 

 scraps of information that are scattered here and there in the 

 storehouse of human intelligence. How often, when walking 

 or bicycling in an unfamiliar country, does one turn into a 

 lane, wondering whether it is to lead one into a new highway 

 or end blindly , forcing the traveler to retrace his path ! Fortu- 

 nately, the many discoveries and inventions based on studies 

 by previous generations made without any expectation of a 

 practical outcome, have silenced those who scoff at anybody 

 who looks for something that cannot at once be made into a 

 scarf-pin or shoe-buttoner or patent medicine or the like. 



Among the matters that will necessarily escape practical 

 application longest are the infinitely great and the infini- 

 tesimally small. It is true enough that astronomy is a useful 

 science to the navigator and to the geographical surveyor; 

 but it would be hard to convince me that, for many genera- 

 tions to come, the price of iron will be affected by our knowl- 

 edge that huge quantities of that metal exist in the solar 

 atmosphere. Nevertheless, it gives us a wonderfully encourag- 

 ing realization of the power of the human intellect to con- 

 template the steps by means of which this apparently useless 

 bit of knowledge was secured. How grand is the thought that 

 a Lilliputian man has been able to weigh heavenly bodies 

 far bigger than the earth itself, and so far distant that our own 

 distance from the sun becomes quite small by comparison! 



1 A popular address evidently delivered in the spring of 1906; the place and exact 

 time are unknown. This address was illustrated by experiments. [EDITOR.] 



