NOTICE BY PROF. J. LOVERING. 429 



taken a new departure under the name of electro-magnetism. 

 Oersted, of Copenhagen, Imd kindled the flame, which parsed rapidly 

 irom hand to hand among the scientific workers of Europe, until it 

 culmmated in the splendid generalization of Ampere. This west- 

 ern contment may have been tardy in welcoming the bright light 

 in the east, but the response, when given, was not a fire, biit a 

 conflagration. Professor Henry led in the new line of physical 

 research with a self-born enthusiasm which seven hours of daily 

 teachmg in mathematics could not extinguish or cool. The limits 

 of this notice forbid a lengthened statement of his contributions to 

 electro-magnetism. But the fertile principle which he deduced 

 Irom his experiments must not be passed over in silence. His dis- 

 tinction between quanUty and intemUy magnets, and between 

 quantity and intermty batteries, (though now differently expressed ) 

 IS all-important and of manifold applications. Every experiment 

 with electro-magnetism, in the laboratory, in the lecture-room, and 

 m the arts, is a success or a failure in proportion as this law is 

 obeyed or ignored. If this discovery has linked Professor Henry's 

 name with the telegraph especially, it is because that was the great 

 problem of the hour, — unsolved, and as some supposed unsolvable 

 It IS not easy to draw the dividing line between the merits of the 

 discoverer and the inventor, when one follows closely upon the heels 

 ot the other. Professor Henry's contribution to the final triumph 

 w^ large, and brilliant, and indispensable ; but it wa^ not all- 

 suflicient. An alphabet was wanting ; a sustaining battery must be 

 invented.; moreover, a man must appear with a capacity for busi- 

 ness and a courage born of hope, with no original knowledge of the 

 fami lar laws of electricity but with an easy absorption of the science 

 of other men, who, by a happy combination of experimented, devices 

 and the devotion of years, might finally achieve a grand ■ commer- 

 cial success In view of Professor Henry's. additional conquests in 

 the realm of physical research, science will ever rejoice that he was 

 not himself dazzled by the inviting prospect of riches and popular 

 applause; that he renounced the fruits of invention when they 

 were almost within his grasp; that he preferred to any short-lived 

 meteoric display the chance of shining for ever as a star in the 

 upper heavens, with Agassiz, Cuvier, and Faraday. : , - 



