This goes counter to the raw food advocates, but here Metchnikoff has the best of the argument. He also questions the advisability of excessive chewing as advocated by Mr. Fletcher, and cites cases where the health has been injured by the practice and the resulting disease cured by more rapid eating.[4]
As soon as Doctor Metchnikoff first made known his theory, the public, always on the lookout for a new "Elixir of Life", demanded fermented milk and the supply was immediately forthcoming, not always of a satisfactory character. Many of the cultures sold in powder or tabloids for the purpose or dispensed in drink at the soda fountains are inactive and useless, or contain other and sometimes undesirable forms of bacteria. I have found it easy enough to prepare the fermented milk in the household, where the proper cultures are to be had. All that is necessary is to sterilize the milk by heating it to the boiling point or near it and keeping it there for ten minutes; then cool quickly to 100° Fahr. and add the ferment in tabloids or powder or some of the former batch, and keep covered at this temperature for twelve hours. A vacuum bottle or fireless cooker is convenient for keeping the temperature even. The fermented milk properly prepared is somewhat thickened, slightly acid, and palatable even to those who do not like ordinary buttermilk.
Metchnikoff's views as to the value of lactic acid have met with not only the legitimate skepticism and criticism of the medical profession, but also with the usual ridicule from the press. "Who would want to live one hundred and fifty years if he had to drink sour milk three times a day?" is asked, and he is alluded to as "the modern Ponce de Leon searching for the Fountain of Immortal Youth and finding it in the Milky Whey." Of course Metchnikoff should not be held responsible for the exaggerated expectations founded upon his theories or for the fakes foisted upon the public in his name. He is indeed an original thinker and a bold experimenter, but he is not a sensationalist or a seeker for popular applause. He has never said that he expected to live one hundred and fifty years or that any one else could by following his regimen. But he does regard that period as more nearly the normal length of human life than the commonly accepted limit of sixty-five or seventy, and as possibly attainable through the advance of medical science. Though he comes of a short-lived family and all his brothers died at an age much younger than he has now attained, his health is unusually good for a man of seventy, and he is as hard-working and enterprising as ever. It is not the mere prolongation of life for which he is working, but the prolongation of the period of serviceable and enjoyable life. If he had remained in the University of Odessa, he would have been retired from his professorship on the ground of old age in 1900, the year before he published his second and greatest work, that on "Immunity in Infectious Diseases."