particular truth, and quickly came to the point. In lecturing, his
personal magnetism counted for much; he readily communicated his
enthusiasm to others.

He was easily moved to tears or to laughter. In his earlier life he
was seldom angry, or seldom showed it, but otherwise made no attempt to
hide his feelings, being a perfect child of nature. Later he became
less demonstrative, save when he was angry. In the last twenty years of
his life he not infrequently lost his temper, though he would not
utterly forget what he was saying; and, however heated the discussion
might become, he never ceased to be a gentleman. Neither indecency nor
aught approaching thereto ever issued from his lips. As a youth in
Switzerland, during his life as a student, and even when he was a
teacher at Neuchatel, he was fond of singing, and he liked to yodel
after the fashion of the Swiss and Tyrolese mountaineers, but he gave
this up when he came to America.

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