Atf ADbRfiSS TO STUDENIS. 413 
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 properties 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 illuminated 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 amazing 
extent the human mind lias 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 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 
discipline 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 un- 
raveling of a language. 
I have thus far confined myself to the purely intellectual 
iside of this question. But man is not all intellect. If he 
were so, science would, I believe, be his proper nutriment. 
But he feels as well as thinks; he is receptive of the 
sublime and beautiful as well as of the true. Indeed, I 
believe that even the intellectual action of a complete man 
is, consciously or unconsciously, sustained by an under- 
current of the emotions. It is vain to attempt to separate 
the moral and emotional from the intellectual. Let a man 
but observe himself, and he will, if I mistake not, find 
that in nine cases out of ten the emotions constitute the 
motive force which pushes his intellect into action. The 
reading of the works of two men, neither of them imbued 
