Pastéurization, adequately carried four in properly designed apparatus, and conveniently controlled) in practice by the phosphatase test, destroys all pathogef organisms in milk and renders it safe fdr human consumption. The laboratory and feld evidence for these statements is too extensive to quote in detail. Reference may, however, be made to ihe now well-known observations of Price in Toronto, which have all the force of an ad hoc experiment. Briefly, she found that among 300 tuberculous children bacteriologically examined, 15 per cent were infected with the bovine tubercle bacillus. All of these had come from parts of Ontario where pasteurization of milk was not carried out. In Toronto itself, where pasteurization has been compulsory since 1915, not a single case of bovine infection was found, in spite of the fact that 26 per cent of the incoming pooled supply of raw milk before pasteurization contained living tubercle bacilli. Nearer home we may add the recent experience at the Hannah Dairy Research Institute gained during one of the calf-feeding experiments alluded to above. Of 36 calves fed for twelve weeks on raw milk, no fewer than 24 were found, when slaughtered, to be infected with the tubercle bacillus and to have imacroscopie lesions of tuberculosis, whereas of 37 calves fed on milk from same source after holder pasteurization, not a single one appeared to be infected. Apart from tuberculosis, the value of pasteurization in protecting against epidemic disease is- well demonstrated by experience in the United States. Examination of the statistical returns shows that milk-borne disease has been practically eliminated from the large cities, where the great majority of the milk is pasteurized, and is now almost entirely confined to the rural districts and smaller towns, where most of the mill is consumed raw. The effect of pasteurization in bringing to an end milk-borne epidemics that are already under way has been frequently and forcibly illustrated during the course of the past few years in Great Britain, notably in the extensive outbreak of typhoid fever at Bournemouth in 1936.
Text read from the printed page and cleaned; old type leaves the occasional error.