Agassiz spoke French with a slight drawl characteristic of the section of Switzerland in which he was born. When he came to America in 1846, he rapidly acquired a command of English, and he eventually wrote and spoke the language with great facility, though his speech never ceased to betray his foreign origin. [Footnote: See Clara Conant Gilson, in the article just cited: He had a few striking peculiarities of pronunciation, one or two of which cling to me with great pertinacity even now. One, in particular, is fresh in my memory. For example, the words respiratory and perspiratory he would accent on the third syllable--_rat_; and, bless me, if to this day I don't have to think twice before I am sure which is right! This shows what indelible impressions his words left upon his pupils.] With his superabundant physical, mental, and emotional energy, he was a natural orator; he was fond of an audience, and gratified by applause. No one ever possessed a greater talent for making natural science popular; even when his discourse became highly technical, his auditors hung upon his words. His method of exposition was very clear and simple. He studiously avoided the error of dragging the listener through all the processes by which the speaker has arrived at a 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.