AN ADDRESS TO STUDENTS. 95 



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 il- 

 luminated by a sun which, though nearly a hundred 

 millions 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 amaz- 

 ing extent the human mind has conquered these things, 

 and revealed the logic which runs through them. 

 Were they facts only, without logical relationship, 

 science might, as a means of discipline, suffer in com- 

 parison with language. But the whole body of pheno- 

 mena 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. Indeed, I 

 believe it would be possible so to limit and arrange 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 language. 



I have thus far confined myself to the purely intel- 

 lectual side of this question. But man is not all in- 



