AN ADDRESS TO STUDENTS. 95 



conquered vast regions of it, have learned their polities 

 and the play of their powers. We live upon a ball of 

 8,000 miles in diameter, swathed by an atmosphere 

 of unknown height. This ball has been molten by 

 heat, chilled to a solid, and sculptured by water. It 

 is made up of substances possessing distinctive pro- 

 perties and modes of action,, which offer problems to 

 the intellect, some profitable to the child, others taxing 

 the highest powers of the philosopher. Our native 

 sphere turns on its axis, and revolves in space. It 

 is one of a band which all do the same. It is illumi- 

 nated by a sun which, though nearly a hundred mil- 

 lions of miles distant, can be brought virtually into 

 our closets and there subjected to - examination. It 

 has its winds and clouds, its rain and frost, its light, 

 heat, sound, electricity, and magnetism. And it has 

 its vast kingdoms of animals and vegetables. To a 

 most amazing extent the human mind has conquered 

 these things, and revealed the logic which runs through 

 them. Were they facts only, without logical relation- 

 ship, science might, as a means of discipline, suffer in 

 comparison with language. But the whole body of 

 phenomena is instinct with law; the facts are hung on 

 principles, and the value of physical science as a means 

 of discipline consists in the motion of the intellect, 

 both inductively and deductively, along the lines of 

 law marked out by phenomena. As regards the disci- 

 pline to which I have already referred as derivable 

 from the study of languages, that, and more is 

 involved in the study of physical science. In- 

 deed, I believe it would be possible so to limit and ar- 

 range the study of a portion of physics as to render 

 the mental exercise involved in it almost qualitatively 

 the same as that involved in the unravelling of a lan- 

 guage. 



