HIS MERITS AS A LECTURER. 323 



cedented opportunities for doing good, he often referred to 

 the great responsibility which, under the circumstances, 

 rested upon him, and of the vast importance it was that at 

 the outset the standard of lectures should be made as high 

 as possible. He was unwearied in his endeavors to meet 

 the occasion suitably. Those who listened to him, and 

 saw everything pass off so easily, every experiment in 

 its place, and almost invariably a success, knew nothing 

 of the thought and labor which preceded in the prepara- 

 tions. After a quarter of a century, he spoke to me of the 

 anxiety which these duties had cost him. 



His lectures on chemistry and geology were given in the 

 Odeon, the largest building in Boston devoted to such pur- 

 poses, and capable of holding about fifteen hundred per- 

 sons, and on his evenings every seat was pretty sure to be 

 filled. Such audiences to popular lectures on scientific 

 subjects were, it is believed, until then, wholly unknown. 

 They certainly excited the wonder and astonishment of 

 foreign and scientific men who came amongst us. His 

 gifts as a teacher were of such marked excellence that it is 

 not easy to do justice to them. There was a charm in his 

 cordial manner and genial temperament which attracted 

 all, and a sympathy at once grew up between himself and 

 his audience. As he entered the room, they were assured 

 by the dignity of his presence and the earnestness of his 

 manner that his heart was in the work. The best evidence 

 of his power is to be found in the fact that he was able to 

 hold the attention of so large a number for two consecu- 

 tive hours, with only a short recess, notwithstanding it had 

 become the established usage in the community that a lect- 

 urer was expected not to exceed a single hour. The feel- 

 ing manifested toward him was that of reverence. The 

 refined and educated classes were always largely repre- 

 sented at his lectures ; and there are not a few who can 

 fairly trace to the inspiration of these the beginning of a 

 scientific career. It may be fairly claimed that no one in 



