Columbia Encyclopedia
Search results
321 results found
Hill, Archibald Vivian
(Encyclopedia)Hill, Archibald Vivian, 1886–1977, British physiologist, B.A. Cambridge, 1909. Hill was a professor at Manchester Univ. (1920–23) and University College, London (1923–25) before becoming a resea...producer gas
(Encyclopedia)producer gas, fuel gas consisting chiefly of carbon monoxide and nitrogen. It is prepared in a furnace or generator in which air is forced upward through a burning fuel of coal or coke. Although the f...convulsion
(Encyclopedia)convulsion, sudden, violent, involuntary contraction of the muscles of the body, often accompanied by loss of consciousness. It is not known what causes the abnormal impulses from the brain that resul...gram-molecular weight
(Encyclopedia)gram-molecular weight, amount of a molecular substance whose weight, in grams, is numerically equal to the molecular weight of that substance. For example, one gram-molecular weight of molecular oxyge...biosphere
(Encyclopedia)biosphere, irregularly shaped envelope of the earth's air, water, and land encompassing the heights and depths at which living things exist. The biosphere is a closed and self-regulating system (see e...aviation medicine
(Encyclopedia)aviation medicine, scientific study of the biological effects of aviation, especially on human beings. Although aviation medicine is concerned with such problems as the spread of diseases by persons t...gills, in biology
(Encyclopedia) CE5 Gills of a fish: Side view (A) and ventral view (B) gills, external respiratory organs of most aquatic animals. In fishes the gills are located in gill chambers at the rear of the mouth (phary...hydrogen
(Encyclopedia)hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...hydroxyl group
(Encyclopedia)hydroxyl group hīdrŏkˈsĭl [key], in chemistry, functional group that consists of an oxygen atom joined by a single bond to a hydrogen atom. An alcohol is formed when a hydroxyl group is joined by ...putty
(Encyclopedia)putty, commonly a mixture of whiting (calcium carbonate) and boiled linseed oil. Other substances may be combined with the oil to make putties suitable for some specific purpose. For example, the red ...Browse by Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
-
Places
+-
- Africa
- Asia
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-
