A can large enough to hold 100 pounds of water would hold 103.2 pounds of average milk at 60 degrees, 103.6 pounds of skim milk, or 90 pounds of pure butterfat. Cream weighs less than water. The butterfat in milk is in the form of little particles or globules, which float around in the milk. In Holstein milk they are small, in Jersey milk they are larger. Cream is simply milk containing a large number of particles of fat. =Legal Requirements.= The law requires market milk to test not less than 3% butterfat. Milk containing 3% butterfat but less than 11¹⁄₂% total solids is usually considered watered milk. We determine fat content by Babcock test and the solids-not-fat by an instrument called the lactometer, which is simply an accurate means of determining the weight of milk. Milk from cows known to be diseased, or from cows fifteen days before coming fresh can not legally be sold. After freshening, milk can be sold as soon as it attains a normal condition. It is illegal to sell milk to which water or any other substance has been added, or milk which has been exposed to disease-producing bacteria, or milk that has been stored, handled or transported in an unclean or unsanitary manner. =Cleanliness.= The greatest handicap in the milk business is the difficulty of getting milk that is as clean as other food which people eat. It is not impossible to do, but it is rarely done. In most all cities of the United States milk that meets the highest requirements as to cleanliness and sanitation is being sold for from 20 to 35 cents a quart. Such milk is guaranteed to be pure by a medical board and is labeled certified milk. There are various requirements in producing certified milk that need not all be explained here. But to the average consumer the main difference is that the producer of certified milk is as careful concerning cleanliness in milking and caring for the milk as a clean, respectable housekeeper is in making bread. In regular market milk we do not require cleanliness up to the standard for certified milk, but all producers and dealers in milk should recognize and admit the truth that common milk is not nearly as clean as it should be.