“Only temporarily. There are other more immediate considerations. For one thing, there are both diphtheria and typhoid near by, and the people on the farm are in contact with them. That’s dangerous. You see, milk under favorable conditions is one of the best cultures for germs that is known. They flourish and multiply in it past belief. The merest touch of contamination may spread through a whole supply, like fire through flax. One more thing: one of your cows, I fear, is tuberculous.” “We might pasteurize, I suppose,” suggested Mrs. Clyde anxiously. Dr. Strong returned a decisive negative. “Pasteurized milk is better than poisoned milk,” he said; “but it’s a lot worse than good raw milk. Pasteurizing simply means the semi-cooking of all the varieties of germs, good and bad. In the process of cooking, some of the nutritive quality is lost. To be sure, it kills the bad germs, but it also kills the good ones.” “Do you mean that some of the germs are actually useful?” asked Mrs. Clyde. “Very useful, in certain rôles. For example, the lactic acid bacteria would be unpopular with you, Mrs. Clyde, because they are responsible for the souring of milk. But they also perform a protective work. They do their best to destroy any bacilli of disease which may invade their liquid home. Now, when you pasteurize, you kill all these millions of defenders; and any hostile germs that come along afterward and get into the milk, through dust or other mediums, can take possession and multiply without hindrance. Therefore pasteurized milk ought to be guarded with extra care after the process, which it seldom is. I once visited a large pasteurizing plant which made great boasts of its purity of product, and saw flies coming in from garbage pail and manure heap to contaminate the milk in the vats; milk helpless to protect itself, because all its army of defense had been boiled to death.” “If we are allowed neither to use our farm milk raw nor to pasteurize it, what shall we do with it?” inquired Mr. Clyde. “Full directions are in there,” answered Dr. Strong, pointing to an envelope on his desk. “If you’ll look over what I’ve written, and instruct your farmer to follow it out, you’ll have milk that is reasonably good. I’ll go further than that; it will be even good enough to give to the babies of the tenements, if you should have any left over.” Mr. Thomas Clyde proceeded to rub his chin, with some degree of concentration, whereby Dr. Strong knew that his hint had struck in. “Meantime,” said Mrs. Clyde, with a trace of sarcasm, “do you expect us to live on condensed milk?” “Not at all; on certified milk.” “What’s that mean?” asked Miss Julia, who had a thirst for information. “What’s a certificate, Junkum?” retorted the doctor. “That’s what I get when I pass my examinations.”