Metchnikoff, Massol and several other authors have recommended fermented sour milk as prepared in Bulgaria, or a similar product, prepared according to Metchnikoff's method from pure cultures of bacteria, as a panacea for many ills. Appendicitis, tropical dysentery, typhoid fever and other diseases are said to be cured or at least benefited by the treatment with sour milk or buttermilk. Intestinal putrefaction, intestinal autointoxication and some nervous and digestive derangements said to be brought about by these conditions are supposed to be favorably influenced by sour-milk therapy, and consequently, according to Metchnikoff, the habitual use of sour milk prepared with the Bulgarian bacillus is conducive to long life. As support to this last suggestion it is stated that in Bulgaria there are relatively more centenarians than in other countries of Europe. Other, factors, however, such as race predisposition, outdoor life and absence of effeminating luxuries, which might contribute to a