spread from a single cow to every one in the herd. It is still by some authorities claimed that there is no authentic case of transmission of bovine tuberculosis to the human system. Other authorities hold that such transmission is possible, even if it has not been proven in a particular case. Since experts disagree on this point the same rule is applicable here as in other cases of the same kind, namely, where experts disagree on a point relating to the public health the benefit of the doubt, if any, should be given to the public, and the advice of those experts followed which is the most radical respecting the protection of health from infection of any kind. It would be difficult to prove, for example, in any case of tuberculosis in man that it had been contracted from the sputa of tuberculosed patients, yet because it is possible, in the opinion of many experts, that such infection and transmission of disease can take place, it is the part of wisdom to guard against it.
It is, I think, a statement which will be accepted by all that it is possible in this country to secure and keep a sufficient number of healthy cows to give the milk supply of the nation. Therefore, it is the duty of the state, either by municipal, state, or federal inspection, to eliminate, as far as possible, and, if necessary, at the expense of the state, every diseased animal from the dairy herd. The farmer whose herd becomes infected through no fault of his can justly claim a compensation for the destruction of his animals for the common good. There is, perhaps, no more important point connected with the keeping of sanitary conditions than the proper inspection of the dairy, not only furnishing milk for family use, but especially for sale. It is the plain duty of every municipality and state to prohibit the sale of milk to its citizens from dairies which are not periodically and frequently subjected to the most rigid expert inspection. Such inspection would not only secure the health of the animals but tend directly toward the cleanliness of the dairy. Only by the exercise of unusual care is it possible to keep milk from becoming contaminated.
Preparation of Milk.—Every part of the animal, especially the udders, should be kept scrupulously clean by proper currying and washing. The milk should be collected in vessels with as small an orifice as possible. As soon as drawn the milk should be strained and artificially cooled to a temperature of at least 50 degrees F., if not lower. A convenient apparatus for cooling the milk is shown in Fig. 14. In this condition, without being exposed to infection and being protected from every point by closed vessels, stoppered when necessary by sterilized cotton, the milk is conducted into sterilized bottles and again stoppered with a sterilized cork of some description. The milk is kept cold until delivered to the consumer and by the consumer should be kept cold until used. By following these precautions it is possible to deliver a pure, wholesome, unpasteurized milk in a condition which keeps practically unchanged for even a longer period than twenty-four hours.
Certified Milk.—Dairies which are inspected either by operation of the
