The most important specific diseases that have been disseminated through subsequent pollution of the milk are typhoid fever, diphtheria, scarlet fever and cholera, but, of course, the possibility exists that any disease germ capable of living and thriving in milk may be spread in this way. In addition to these diseases that are caused by the introduction of specific organisms (the causal organism of scarlet fever has not yet been definitely determined), there are a large number of more or less illy-defined troubles of an intestinal character that occur especially in infants and young children that are undoubtedly attributable to the activity of microorganisms that gain access to milk during and subsequent to the milking, and which produce changes in milk before or after its ingestion that result in the formation of toxic products. DISEASES TRANSMISSIBLE FROM ANIMAL TO MAN THROUGH DISEASED MILK. ~Tuberculosis.~ In view of the wide-spread distribution of this disease in both the human and the bovine race, the relation of the same to milk supplies is a question of great importance. It is now generally admitted that the different types of tubercular disease found in different kinds of animals and man are attributable to the development of the same organism, _Bacillus tuberculosis_, although there are varieties of this organism found in different species of animals that are sufficiently distinct to permit of recognition. The question of prime importance is, whether the bovine type is transmissible to the human or not. Artificial inoculation of cattle with tuberculous human sputum as well as pure cultures of this variety show that the human type is able to make but slight headway in cattle. This would indicate that the danger of cattle acquiring the infection from man would in all probability be very slight, but these experiments offer no answer as to the possibility of transmission from the bovine to the human. Manifestly it is impossible to solve this problem by direct experiment upon man except by artificial inoculation, but comparative experiments upon animals throw some light on the question. Theo. Smith[81] and others[82] have made parallel experiments with animals such as guinea pigs, rabbits and pigeons, inoculated with both bovine and human cultures of this organism. The results obtained in the case of all animals tested show that the virulence of the two types was much different, but that the bovine cultures were much more severe. While of course this does not prove that transmission from bovine to human is possible, still the importance of the fact must not be overlooked. In a number of cases record of accidental infection from cattle to man has been noted.[83] These have occurred with persons engaged in making post-mortem examinations on tuberculous animals, and the tubercular nature of the wound was proven in some cases by excision and inoculation.