With the exception of my call at the office of the American Legation, I made but a single visit to any person in Paris. That person was M. Pasteur. I might have carried a letter to him, for my friend Mrs. Priestley is well acquainted with him, but I had not thought of asking for one. So I presented myself at his headquarters, and was admitted into a courtyard, where a multitude of his patients were gathered. They were of various ages and of many different nationalities, every one of them with the vague terror hanging over him or her. Yet the young people seemed to be cheerful enough, and very much like scholars out of school. I sent my card in to M. Pasteur, who was busily engaged in writing, with his clerks or students about him, and presently he came out and greeted me. I told him I was an American physician, who wished to look in his face and take his hand,--nothing more. I looked in his face, which was that of a thoughtful, hard-worked student, a little past the grand climacteric,--he was born in 1822. I took his hand, which has performed some of the most delicate and daring experiments ever ventured upon, with results of almost incalculable benefit to human industries, and the promise of triumph in the treatment of human disease which prophecy would not have dared to anticipate. I will not say that I have a full belief that hydrophobia--in some respects the most terrible of all diseases--is to be extirpated or rendered tractable by his method of treatment. But of his inventive originality, his unconquerable perseverance, his devotion to the good of mankind, there can be no question. I look upon him as one of the greatest experimenters that ever lived, one of the truest benefactors of his race; and if I made my due obeisance before princes, I felt far more humble in the presence of this great explorer, to whom the God of Nature has entrusted some of her most precious secrets. There used to be--I can hardly think it still exists--a class of persons who prided themselves on their disbelief in the reality of any such distinct disease as hydrophobia. I never thought it worth while to argue with them, for I have noticed that this disbelief is only a special manifestation of a particular habit of mind. Its advocates will be found, I think, most frequently among "the long-haired men and the short-haired women." Many of them dispute the efficacy of vaccination. Some are disciples of Hahnemann, some have full faith in the mind-cure, some attend the séances where flowers (bought from the nearest florist) are materialized, and some invest their money in Mrs. Howe's Bank of Benevolence. Their tendency is to reject the truth which is generally accepted, and to accept the improbable; if the impossible offers itself, they deny the existence of the impossible. Argument with this class of minds is a lever without a fulcrum.