Considerably less than of the milk sugar. Usually about half the quantity (half an ounce to twenty ounces of food) is as much as most infants can digest If the same quantity is used as of the milk sugar, the food is made unduly sweet, and the sugar is likely to ferment in the stomach and cause colic. _Is not the purpose of the sugar to sweeten the food in order to make it palatable?_ Not at all; although it does that, its real use is to furnish one of the essential elements needed for the growth of the body, and the one that is required by young infants in the largest quantity. _How do we know that this is so?_ By the fact that in good breast milk the amount of sugar is greater than that of the fat, proteids, and salts combined. _We have seen that cow's milk has nearly three times as much proteids (curd) and salts as mother's milk. How are these to be diminished?_ By diluting the milk. _Will it be sufficient to dilute the milk twice (i.e., add two parts of water to one part of milk)?_ Not for a very young infant. Although this will give about the quantity of proteids present in mother's milk, the proteids of cow's milk are so much more difficult for the infant to digest, that in the beginning it should be diluted five or six times for most infants. _If cow's milk is properly diluted and lime-water and sugar added does it then resemble mother's milk?_ No; the mixture contains too little fat. _What is the easiest way of overcoming this?_ By increasing the fat in the milk before dilution. It may be done by using top-milk or a mixture of milk and cream. _What is top-milk?_ It is the upper layer of milk removed after standing a certain number of hours in a milk bottle, glass jar, or any tall vessel with straight sides. It contains most of the cream and some of the milk just below. The strength of the top-milk is measured by the fat it contains--e.g., a 10-per-cent milk contains 10 per cent fat; 7-per-cent milk contains 7 per cent fat, etc. These are the two strengths of top milk most used in infant feeding. _On what does the percentage of fat in top-milk depend?_ 1. On the length of time the milk has stood. 2. On the manner in which the top-milk is removed. 3. On the number of ounces removed. 4. On the richness of the milk used. Unless these are known it is impossible to say even approximately how strong in fat the top-milk is. _When and how should top-milk be removed?_ If milk fresh from the cow, or before the cream has risen, is put into bottles and rapidly cooled, the top-milk may be removed in as short a time as four hours. In the case of bottled milk it makes little difference if it stands a longer time, even until the next day. The best means of removing it is by a small cream-dipper[2] holding one ounce; although it may be taken off by a spoon or siphon. It should not be poured off.