Milk is found to contain all three vitamins, A, B, and C, known as the fat-soluble A, water-soluble B, and water-soluble C. Cream is rich in vitamin A. This vitamin increases growth and promotes nutrition and is therefore valuable in the diet of the young. Vitamin A and B are not destroyed by heat, unless it be a very great degree for a long period of time; they also resist drying and age. For this latter reason milk may be used in cooking and still retain the virtues of these two vitamins, as well as do evaporated milk and dried milk. Vitamin C is impaired and may be completely destroyed by high temperature and deteriorates with age and with drying. There is no article of food (diet) that is superior to milk in dietetic and nutritional value, and especially is this true of butter fat. The standard by which milk is tested is the amount of butter fat it contains. Lactose or Milk Sugar Milk contains what is known as milk sugar or lactose. It is white crystalline sugar, has a slightly sweet taste and is soluble in water. When acted upon by microörganisms it is changed into glucose, and the glucose is then reduced to lactic acid, the lactic acid being the cause of the milk souring. Milk sugar is found nowhere else in Nature. SANITARY MEASURES IN PRODUCTION Milk, a Germ Medium Milk, because of its characteristic qualities, forms a medium in which all kinds of bacteria and germs, or low forms of life, thrive. When we consider the processes necessary to obtain the milk and deliver it to the consumer, even though the most rigid sanitary methods are observed, it can readily be seen that milk is exposed to almost all kinds of dirt and to the different forms of organisms. It is very difficult to obtain milk in a state of purity and if germs played as important a part in the production of dis-ease as is thought by some, one of the most important articles of diet would be lost to mankind. Great quantities of these germs are ingested into the stomach of individuals who drink milk. These bacteria are carried into the milk during milking and in the handling of the milk and the retainers. Bacteriological standards have been established, but vary a little with different authors. Usually it is agreed that certified milk should not contain more than 10,000 bacteria per cubic centimeter. Market milk should not have more than 1,000,000 bacteria per cubic centimeter in the raw state and not more than 50,000 per cubic centimeter after pasteurization.