BOUILLON, a watery extract made from beef, and widely used as an appetizer. The finely cut meat is slowly boiled in water, the solidified fat removed after cooling, and the liquid strained, thus removing the meat fragments and coagulable proteins. The bouillon cubes of commerce are made by adding salt and a plant extract, and evaporating nearly to dryness. The caloric value of bouillon is only one-fourth that of orange juice and one seventh that of whole milk, and it is obviously by no means a nutritive beverage. Its active principles are the purin bases, to which its appetizing flavour is due, and which directly stimulate the secretion of gastric juice. It is widely used for invalids to encourage appetite and digestion.