In children, also, we can see the bad effects of using boiled milk. It has been shown by many authors that Barlow’s disease and rickets may be due to drinking overheated milk, especially when such milk is not fresh. Behring has now shown by experiments that when calves are fed on boiled milk they acquire rickety deformities of the bones and scorbutic conditions. The majority of the calves died from exhausting diarrhœas, just as do infants in large cities. Thus it is evident that we should always use raw milk, and only when there is doubt as to the origin of the milk should we heat it, and then not above 60° to 70° C. (140 F.), so as not to destroy all its valuable properties. Considering the enormous importance of this question for the public welfare, it would be advisable to put all establishments for the supply of milk under the control of physicians or veterinary surgeons. As the welfare of many children depends upon the condition of the cow that is giving them its milk, cows should be kept with great care and regarded as a kind of wet nurse. Just as prisoners, or men who work all day in close and badly ventilated rooms, are apt to develop tuberculosis; so, also, are cows if they are kept in dark stables with no fresh air. Therefore cows should be let out to pasture on the meadows every day, and kept there at night if the weather permits. The milk is also improved in quality if the cow gets some food rich in proteids in addition to her grain and hay. Every cow should be tested by tuberculin injections, and if this is positive the animal should be destroyed. The milking of the cows should be done with scrupulous cleanliness. The udders and surrounding parts should be washed, and the milkers themselves should be dressed in clean white clothes, and their hands should be clean, preferably by washing them with some antiseptic liquid. Unless the cow is tubercular or otherwise sick, its milk never contains any harmful substances. As soon as it is obtained the milk should be put into an ice chest, as this is the best way to preserve it, and air should be excluded. It has been shown that milk cooled off to -16° C. does not lose its good qualities, and can be kept in fresh condition for many days. By undergoing acid fermentation milk does not lose its valuable properties. Important substances like lecithin, iron, lime, native albumin, and valuable ferments are contained in such milk. Whey and buttermilk are also milk foods of the highest value.