The New Student's Reference Work/Albumen

Albu'men, a substance familiarly known in the white of eggs, which exists abundantly in all animals and in the juices, seeds, grains and other parts of plants. It is one of a class of substances called proteids, which form an important part of food, since they build up the tissues of the body. Albumen is naturally a fluid, but when heated to a high temperature it is changed into a firm, white solid. White of egg is used to clear liquids, as coffee, because when boiled it collects all the impurities in flakes and rises to the surface as scum, or sinks to the bottom, according to the weight of the liquid holding it.