Columbia Encyclopedia

Search results

336 results found

phenolphthalein

(Encyclopedia)phenolphthalein fēˈnôlthălˈēən [key], or 2,2-Bis(p-hydroxyphenyl) phthalide, C20H14O4, crystalline organic compound. It is used medicinally as a laxative and is widely employed in the laborator...

potassium hydroxide

(Encyclopedia)potassium hydroxide, chemical compound with formula KOH. Pure potassium hydroxide forms white, deliquescent crystals. For commercial and laboratory use it is usually in the form of white pellets. A st...

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...

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...

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...

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...

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...

agrimony

(Encyclopedia)agrimony ăgˈrĭmōˌnē [key], any plant of the genus Agrimonia, perennials of the family Rosaceae (rose family) native to north temperate zones, to Brazil, and to Africa. They are found wild in the...

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...