Columbia Encyclopedia
Search results
336 results found
Wöhler, Friedrich
(Encyclopedia)Wöhler, Friedrich frēˈdrĭkh vöˈlər [key], 1800–1882, German chemist. He studied under the German chemist Leopold Gmelin and J. J. Berzelius, a Swedish chemist, and in 1836 was appointed profe...calcium carbonate
(Encyclopedia)calcium carbonate, CaCO3, white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. Calci...eye
(Encyclopedia)CE5 Cross section of human eye eye, organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of ey...herbicide
(Encyclopedia)herbicide hrˈbəsīdˌ [key], chemical compound that kills plants or inhibits their normal growth. A herbicide in a particular formulation and application can be described as selective or nonselectiv...mercuric chloride
(Encyclopedia)mercuric chloride or mercury (II) chloride, chemical compound, HgCl2, a white powder of colorless rhombohedral crystals, somewhat soluble in water. It is also called bichloride of mercury or corrosive...Magnus, Heinrich Gustav
(Encyclopedia)Magnus, Heinrich Gustav hīnˈrĭkh go͝osˈtäf mägˈno͝os [key], 1802–70, German chemist, physicist, and educator. In 1831 he became lecturer and in 1834 professor of physics and technology at t...potassium nitrate
(Encyclopedia)potassium nitrate, chemical compound, KNO3, occurring as colorless, prismatic crystals or as a white powder; it is found pure in nature as the mineral saltpeter, or niter. (The name saltpeter is also ...trinitrotoluene
(Encyclopedia)trinitrotoluene or TNT trīˌnīˌtrōtŏlˈyo͞oēn [key], CH3C6H2(NO2)3, crystalline, aromatic compound that melts at 81℃. It is prepared by the nitration of toluene. Trinitrotoluene is a high exp...night blindness
(Encyclopedia)night blindness, inability to see normally in subdued light. It is usually a result of vitamin A deficiency. The rod cells, one of two light-sensitive areas of the retina of the eye, are impaired in t...VX
(Encyclopedia)VX vēˈĕks [key], nerve gas several times more toxic than sarin but less volatile. It kills within minutes if inhaled or deposited on the skin; protection from VX would require both protective suits...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 +-