62 MEMORIAL OF JOSEPH HENRY. 



At Princeton Professor HENRY found congenial companions and 

 duties well suited to his powers. Here he taught and investigated 

 for fourteen fruitful and happy years ; here he professed the faith 

 that was in him, entering into the communion of the Presbyterian 

 Church, in which he and his ancestors were nurtured; and here 

 he developed what might not have been expected a genius for 

 education. One could count on his being a clear expositor, and his 

 gifts for experimental illustration and for devising apparatus had 

 been already shown. But now, as a college professor, the question 

 how to educate came before him in a broader way. He appreciated, 

 and he made his associates and pupils appreciate, the excellence of 

 natural philosophy for mental discipline, for training at once both 

 the observing and the reasoning faculties. A science which rises from 

 the observation of the most familiar facts, and the questioning of 

 these by experiment, to the consideration of causes, the ascertaining 

 of laws, and to the most recondite conceptions respecting the consti- 

 tution of matter and the interplay of forces, offers discipline to all 

 the intellectual powers, and tasks the highest of them. Professor 

 HENRY taught not only the elementary facts and general principles 

 from a fresh survey of both, but also the methods of philosophical 

 investigation, and the steps by which the widest generalizations and 

 the seemingly intangible conceptions of the higher physics have been 

 securely reached. He exercised his pupils in deducing particular 

 results from admitted laws, and in then ascertaining whether what 

 was thus deduced actually occurred in nature ; and if not, why not. 

 Though very few of a college class might ever afterward undertake a 

 physical or chemical investigation, all would or should be concerned 

 in the acquisition of truth and its relations ; and by knowing how 

 truth was won and knowledge advanced in one field of inquiry, 

 they would gain the aptitude which any real investigation may 

 give, and the confidence that springs from a clear view and a sure 

 grasp of any one subject. 



