Boiling as applied to cooking is the application of heat to food products through the medium of boiling, or simmering water. At sea-level water boils at 212°, and simmers at 185° Fahr. Rapid-boiling water, unless the steam be confined, attains no higher temperature and so cooks food no more quickly than water boiling less rapidly. When rapid-boiling water is advisable, as in boiling macaroni, rice, or peas, the object is not to cook more quickly, but to separate the contents by violence of motion and keep them from clinging to the receptacle in which they are cooked. The boiling point of stock and milk is slightly higher than that of water. Milk boils at 214° Fahr.; as this temperature hardens the casein, thus making it less digestible, milk should not be allowed to reach the boiling point; it should be cooked over hot water. When bead-like bubbles appear on the edge of milk next to the dish the milk is scalded. Scalded milk reaches a temperature of 196°. As we wish to retain all the juices in boiled meat, we plunge it, first of all, into boiling water, and after searing over the outside reduce the temperature to the simmering point. Water does not simmer when it is perfectly still, the surface of the liquid should stir gently. When bubbles are formed that break upon the surface, the water boils. While rapid boiling softens the connecting tissues between the little bundles of fibres and causes meat to appear tender, the fibre itself is made soluble only by long slow cooking; also the flavors of meats (and vegetables as well) are volatile, and much of these is carried off in the steam from rapidly boiling water. Thus, it would seem that, save for the hardening of the albumen, reason suffices for cooking meat, after the juices are imprisoned, at the simmering point. Closed vessels aid in retaining flavor.