How these foods compare in fuel value is shown in Fig. 42. [Illustration: FIG. 41.——Composition of milk and cream.] [Illustration: FIG. 42.——100-Calorie portions of milk and cream. No. KIND WEIGHT OF PORTION, OUNCES 1. Cream (18.5% fat) 1.8 2. Whole milk 5.1 3. Skim milk 9.6 4. Buttermilk 9.9 _A. Fowler, Photographer._] =Wholesome and clean milk.=——At present, the milk supply is one of our most pressing community problems, showing how closely the country and the city are united. A case of typhoid fever in one farm family, not properly cared for, may be the seed of a serious epidemic in some town. To insure clean milk to the consumer, and a fair return in money to the producer, is a great sanitary and commercial problem, not to be solved in a day. Milk is a medium in which bacteria flourish, both the harmless and the disease producing. Typhoid fever and other fatal diseases may be carried by milk from unclean barns and dairies, and tuberculosis is possible from diseased cows. The cows must be in good health, and the stable clean. Figure 43 shows a stable with cement floor and good drainage. The cows must themselves be clean, and should be curried and washed. The milkers should have clean clothes and hands, and all receptacles should be sterilized. The milk must be rapidly cooled (see Fig. 44), bottled in sterilized bottles, kept cool during transportation, and delivered as promptly as possible to the consumer. “Certified” milk is produced and handled under the best conditions, but costs at least 15 cents a quart. Since a quart of milk is equivalent to a pound of steak or to 8 eggs, milk even at 15 to 20 cents a quart is more economical than meat and eggs at ordinary prices. At the usual price of 8 to 10 cents a quart, milk is very economical as compared with other perishable foods. [Illustration: FIG. 43.——A modern cow house. _Courtesy of the Walker-Gordon Laboratory._] [Illustration: FIG. 44.——Milk bottling room. _Courtesy of Walker-Gordon Laboratory._]