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sulfuric acid

(Encyclopedia)sulfuric acid, chemical compound, H2SO4, colorless, odorless, extremely corrosive, oily liquid. It is sometimes called oil of vitriol. Although sulfuric acid is now one of the most widely used c...

Natives, North American

(Encyclopedia)Natives, North American, peoples who occupied North America before the arrival of the Europeans in the 15th cent. They have long been known as Indians because of the belief prevalent at the time of Co...

nutrition

(Encyclopedia)nutrition, study of the materials that nourish an organism and of the manner in which the separate components are used for maintenance, repair, growth, and reproduction. Nutrition is achieved in vario...

water pollution

(Encyclopedia)water pollution, contamination of water resources by harmful wastes; see also sewerage, water supply, pollution, and environmentalism. The United States has enacted extensive federal legislation to ...

whaling

(Encyclopedia)whaling, the hunting of whales for the oil that can be rendered from their flesh, for meat, and for baleen (whalebone). Historically, whale oil was economically the most important. In 1932–33, par...

birth control

(Encyclopedia)birth control, practice of contraception for the purpose of limiting reproduction. Although contraceptive techniques had been known in ancient Egypt, Greece, and Rome, the modern movement for birth ...

nervous system

(Encyclopedia)CE5 Nerve cell CE5 Nervous system nervous system, network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. Virtually all members of ...

Leonardo da Vinci

(Encyclopedia)Leonardo da Vinci də vĭnˈchē, Ital. lāōnärˈdō dä vēnˈchē [key], 1452–1519, Italian painter, sculptor, architect, musician, engineer, and scientist, b. near Vinci, a hill village in Tusc...

architecture

(Encyclopedia)architecture, the art of building in which human requirements and construction materials are related so as to furnish practical use as well as an aesthetic solution, thus differing from the pure utili...

AIDS, in medicine

(Encyclopedia)AIDS or acquired immunodeficiency syndrome, fatal disease caused by a rapidly mutating retrovirus that attacks the immune system and leaves the victim vulnerable to infections, malignancies, and neuro...