I found Metchnikoff a delightful companion. He always had something new or of special interest to show to me at the laboratory--some microscopical preparation, the digestive process in Protozoa, the microbian parasite of a water-flea, a new method of dark ground illumination with high powers (Commandant's method for film production), the newly discovered Treponema of syphilis, or the experimental inoculation of a disease under study. Sometimes I would lunch at his house, when, although he neither smoked nor took alcoholic drinks himself, he made a point of giving me first-rate claret and a good cigar. It was about the year 1900 that he arranged for the preparation of a pure "sour milk" made by the use of a special lactic ferment (selected and cultivated by himself), and this he took regularly. I found it a most agreeable food, and for several years made it an article of my own diet. He was very careful about the possible contamination of uncooked food by bacteria and the eggs of parasitic worms, and in consequence had "rolls" sent to him from the bakers each in its separate paper bag, whilst he would never eat uncooked salads or fruit which could not be rendered safe by "peeling." This was not an excess of caution, but resulted from his characteristic determination to carry out in practice the directions given by definite scientific knowledge, and to make the attempt to lead so far as possible a life free from disease. Often when I arrived in Paris he would invite me to lunch at one of the leading cafés, and though he ate very simple food himself took keen pleasure in ordering the best for me and thoroughly enjoyed the change of scene and the amenities of a first-rate restaurant. During one of his visits to London, I remember that he was invited, and I with him, on two or three occasions, by leading London physicians to dinner-parties. He was greatly shocked at the amount of strong wine which his hosts and fellow-guests consumed, and assured me that in Paris it would be injurious to the reputation of a physician were he not to set an example of either abstinence or great moderation.