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tartar

(Encyclopedia)tartar or argol ärˈgəl [key], impure potassium hydrogen tartrate deposited as a crust in fermenting vessels during wine making. When purified, it yields cream of tartar. Tartar is the chief natural...

cyanide

(Encyclopedia)cyanide sīˈənīdˌ [key], chemical compound containing the cyano group, –CN. Cyanides are salts or esters of hydrogen cyanide (hydrocyanic acid, HCN) formed by replacing the hydrogen with a metal...

Thénard, Louis Jacques

(Encyclopedia)Thénard, Louis Jacques lwē zhäk tānärˈ [key], 1777–1857, French chemist. He became professor at the Collège de France (1802), dean of the Faculty of Sciences, Paris (1821), chancellor of the ...

mica

(Encyclopedia)mica mīˈkə [key], general term for a large group of minerals, hydrous silicates of aluminum and potassium, often containing magnesium, ferrous iron, ferric iron, sodium, and lithium and more rarely...

heart-lung machine

(Encyclopedia)heart-lung machine, device that maintains the circulation of the blood and the oxygen content of the body when connected with the arteriovenous system; it is also called the pump oxygenator. The machi...

MacKinnon, Roderick

(Encyclopedia)MacKinnon, Roderick, 1956–, American biochemist, b. Burlington, Mass., M.D. Tufts Univ., 1982. MacKinnon was on the faculty at Harvard Medical School from 1989–96 and has been a professor at the H...

sperm oil

(Encyclopedia)sperm oil, liquid wax obtained from the sperm whale, or cachalot, and related marine mammals. It flows readily, is clear, and varies in color from pale yellow to brownish yellow. Chemically it is not ...

blueprint

(Encyclopedia)blueprint, white-on-blue photographic print, commonly of a working drawing used during building or manufacturing. The plan is first drawn to scale on a special paper or tracing cloth through which lig...

feldspar

(Encyclopedia)feldspar fĕlˈspär [key], an abundant group of rock-forming minerals which constitute 60% of the earth's crust. Chemically the feldspars are silicates of aluminum, containing sodium, potassium, iron...

litmus

(Encyclopedia)litmus, organic dye usually used in the laboratory as an indicator of acidity or alkalinity (see acids and bases). Naturally pink in color, it turns blue in alkali solutions and red in acids. Commonly...