milk sugar: see lactose.

milk snake: see king snake.

milk of magnesia, common name for the chemical compound magnesium hydroxide, Mg(OH)₂. The viscous, white, mildly alkaline mixture that is used medicinally as an antacid and laxative is a suspension of approximately 8% magnesium hydroxide in water.

milk, liquid secreted by the mammary glands of female mammals as food for their young. The milk of the cow is most widely used by humans, but the milk of the mare, goat, ewe, buffalo, camel, ass, zebra, reindeer, llama, and yak is also used. The composition of milk varies with the species, breed, feed, and condition of the animal. Jersey and Guernsey cows produce milk of high butterfat content; Holsteins produce larger quantities of milk but with a lower butterfat content.

Milk prepared for sale is often homogenized; in this process it is pumped under pressure through small openings to break up the milk-fat globules, thus ensuring an equal distribution of fat throughout the milk rather than permitting it to rise to the top as cream. In most countries where milk is a commercial product, it is subject to regulations concerning its composition (i.e., the proportion of butterfat and other solids) and its purity, with sanitary measures in force that cover milk handlers, herds, plants, and equipment. Pasteurization (partial sterilization by heating) checks bacterial growth, thereby making milk safer to drink and increasing its keeping qualities and range of transport.

Milk, an almost complete food, consists of proteins (mainly casein), fat, salts, and milk sugar, or lactose, as well as vitamins A, C, D, certain B vitamins, and lesser amounts of others. (Many people are unable to digest milk after childhood because they stop producing an enzyme needed to break down lactose, but usually they still can digest yogurt, hard cheeses, and lactose-reduced milk products.) Commercial dairies often supplement natural vitamin D with a concentrate. Milk is a major source of calcium and a good source of phosphorus. Low-fat and skim milk fortified with vitamins A and D have the same nutritional value as whole milk, but with fewer calories and less cholesterol. Whole milk has 3.5% milkfat, low-fat milk 1% to 2%, and skim, 0.5%. Heavy cream has a minimum of 36% milkfat, half-and-half not less than 10.5% nor more than 18%.

A patent was issued for the production of dried milk in Great Britain in 1855, and for concentrated milk in the United States to Gail Borden in 1856. The two types of concentrated milk are condensed and evaporated; condensed milk is a sweetened product (over 40% sugar), and evaporated is unsweetened. Dried, or powdered, milk is made by passing a film of partially evaporated milk over a heated drum or by spraying it into a heated chamber in which the particles dry. Malted milk is a dried mixture made of milk and the liquid from a mash of barley malt and wheat flour.

See butter; cheese; dairying; fermented milk.

fermented milk, whole or skim milk curdled to beverage or custardlike consistency by lactic-acid-producing microorganisms. Many forms of fermented milk were used by early nomadic herders, especially in Asia and S and E Europe, Scandinavia, Africa, and South America. Such milks are believed to have medicinal value in the control of intestinal fermentation by contributing bacteria that aid in digestion. Fermented milks include acidophilus milk; cultured buttermilk; kumiss (koumiss), probably originated from mare's milk by western Mongols, effervescent and of acrid flavor and containing alcohol produced by yeasts; the similar kefir of Central Asia; yogurt, similar to the Armenian matzoon; and the Scandinavian beverages, kaeldermaelk and filbunke.

condensed milk: see milk.

acidophilus milk: see fermented milk.

Milk, Harvey, 1931-78, U.S. politician and gay-rights activist. When elected (1977) to the San Francisco Board of Supervisors, he was the first acknowledged homosexual to win high local office in the United States. A liberal Democrat, he supported equal rights for minorities and women. Former city supervisor Dan White assassinated Milk and San Francisco Mayor George Moscone in 1978.

Milk, river, 729 mi (1,173 km) long, rising in the Rocky Mts., NW Mont. It flows N into Alberta, Canada, then in long curves eastward, S into Montana again, and generally SE to the Missouri River, entering just below Fort Peck Dam. The Milk River reclamation project (est. 1911) irrigates c.134,000 acres (54,230 hectares). The largest of several dams is the Fresno Dam (completed 1939). Malta, Chinook, Glasgow, and Harlem, Mont., are in the project area.

Slightly sweet sugar (disaccharide) composed of two monosaccharides, glucose and galactose, linked together. Lactose-intolerant adults, and more rarely infants, cannot digest lactose because they lack the enzyme (lactase) that splits it into simpler sugars and suffer diarrhea and bloating when they eat foods containing it. Lactose, which makes up 2–8percnt of the milk of mammals, is the only common sugar of animal origin. Commercial lactose is obtained from whey, a liquid by-product of cheese. It is used in foods, in pharmaceuticals, and in nutrient broths used to produce penicillin, yeast, and riboflavin, and other products.

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Liquid secreted by the mammary glands of female mammals to nourish their young. The milk of domesticated animals is also an important food source for humans. Most milk consumed in Western countries is from cows; other important sources include sheep, goats, water buffalo, and camels. Milk is essentially an emulsion of fat and protein in water, along with dissolved sugar, minerals (including calcium and phosphorus), and vitamins, particularly vitamin B complex. Commercially processed cow's milk is commonly enriched with vitamins A and D. Many countries require pasteurization to protect against naturally occurring and artificially introduced microorganisms. Cooling further prevents spoilage (souring and curdling). Fat from whole milk (about 3.5percnt fat content) can be removed in a separator to produce cream and leave low-fat milk (1–2percnt fat) or skim milk (0.5percnt fat). Milk is usually homogenized, forced under high pressure through small openings to distribute the fat evenly. It may also be condensed, evaporated, or dehydrated for preservation and ease of transport. Other dairy products include butter, cheese, and yogurt.

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orig. Glimpy Milch

(born May 22, 1930, Woodmere, Long Island, N.Y., U.S.—died Nov. 27, 1978, San Francisco, Calif.) U.S. political leader. After graduating from college, he served in the U.S. Navy and was discharged in 1955 (although Milk claimed that he was dishonourably discharged due to his homosexuality, military records do not support the allegation). He later settled in San Francisco and soon gained a following as a leader of the city's gay community. In 1977 he was elected to the city's Board of Supervisors, becoming one of the first openly gay elected officials in U.S. history. In 1978 Milk and the city's mayor, George Moscone (1929–78), were shot and killed in City Hall by Dan White, a conservative former city supervisor. At White's murder trial, his attorneys argued that his judgment had been impaired by eating junk food (a tactic later derided as the “Twinkie defense”); his conviction on the less serious charge of voluntary manslaughter sparked riots in the city. Milk was the subject of numerous books and movies, including the 1984 documentary The Times of Harvey Milk, which received an Academy Award, and Milk (2008), in which he was portrayed by Sean Penn.

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