Here his recreations were mostly social. He was the friend of Longfellow, Lowell, and Whittier; he was the friend of laborers and fishermen. In society he liked to encounter men of wealth and influence, for he had by nature, and also learned from Alexander von Humboldt, some of the arts of the courtier. 'It would be difficult,' says Dr. Charles D. Walcott, [Footnote: _Smithsonian Miscellaneous Collections_ 50. 217 (1908).] 'to measure his influence in the way of causing men of political and commercial power to realize that the support of scientific research, and the diffusion of knowledge thereby gained, depend largely on them.' In other natural scientists he was prone to discover too much self-satisfaction, and too much personal curiosity, against which he hardly knew how to protect himself. But with the group of younger scientists he himself developed, though now and then one or another grew mutinous, he was, during most of the time, on the best of terms. His own early schooling in the classics gave him a relish for scholars, and he was pleased with the company of historians and lawyers. For military men he did not care, but he liked naval officers and sea-captains. He paid little attention to matters of dress, certainly as regards his own person. He was gratified by the marks of distinction conferred upon him at home and abroad, but took little subsequent thought of the ribbons, badges, and diplomas, keeping them, but not very carefully, and never making a parade of them. Eloquent as a lecturer, he was also brilliant and persuasive in conversation, being, in appearance at least, quite unreserved, and open in his attempt to capture the good will of his auditor. However, if there was no covert artifice, there was at all events the native shrewdness of the Swiss peasant to reckon with, and doubtless the subtlety of genius--which will not, or cannot, always reveal itself in full. In his later years, accordingly, though his winning manners and his desire that you should completely display your thought to him might lead you to suppose him utterly open with you, you might in the end discover that you had not fathomed his soul, that there was that in him which could not be taken captive, and that there might be a silent invincible rejection on his part of something within you which was foreign to him.