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Theodoric the Great

(Encyclopedia)Theodoric the Great, c.454–526, king of the Ostrogoths and conqueror of Italy, b. Pannonia. He spent part of his youth as a hostage in Constantinople. Elected king in 471 after his father's death, h...

chromium

(Encyclopedia)chromium krōˈmēəm [key] [Gr.,=color], metallic chemical element; symbol Cr; at. no. 24; at. wt. 51.9961; m.p. about 1,857℃; b.p. 2,672℃; sp. gr. about 7.2 at 20℃; valence +2, +3, +6. Chromiu...

chain reaction

(Encyclopedia)CE5 Chain reaction: A neutron (n) strikes the uranium nucleus (U-235), causing it to split into fission products A and B and release two neutrons. These neutrons can in turn cause further fissions....

fugitive slave laws

(Encyclopedia)fugitive slave laws, in U.S. history, the federal acts of 1793 and 1850 providing for the return between states of escaped black slaves. Similar laws existing in both North and South in colonial days ...

gasoline

(Encyclopedia)gasoline or petrol, light, volatile mixture of hydrocarbons for use in the internal-combustion engine and as an organic solvent, obtained primarily by fractional distillation and “cracking” of pet...

lithium

(Encyclopedia)lithium lĭthˈēəm [key] [Gr.,=stone], metallic chemical element; symbol Li; at. no. 3; interval in which at. wt. ranges 6.938–6.997; m.p. about 180.54℃; b.p. about 1,342℃; sp. gr. .534 at 20�...

arsenic

(Encyclopedia)arsenic ärˈsənĭk [key], a semimetallic chemical element; symbol As; at. no. 33; at. wt. 74.92160; m.p. 817℃ (at 28 atmospheres pressure); sublimation point 613℃; sp. gr. (stable form) 5.73; va...

Whittier, John Greenleaf

(Encyclopedia)Whittier, John Greenleaf hwĭtˈēər [key], 1807–92, American Quaker poet and reformer, b. near Haverhill, Mass. Whittier was a pioneer in regional literature as well as a crusader for many humanit...

carbon monoxide

(Encyclopedia)carbon monoxide, chemical compound, CO, a colorless, odorless, tasteless, extremely poisonous gas that is less dense than air under ordinary conditions. It is very slightly soluble in water and burns ...

diesel engine

(Encyclopedia)diesel engine, type of internal-combustion engine invented by the German engineer Rudolf Diesel and patented by him in 1892. Although his engine was designed to use coal dust as fuel, the diesel engin...