(Encyclopedia) nitrogen mustard, any of various poisonous compounds originally developed for military use (see poison gas). Like mustard gas and lewisite, it is a vesicant (blistering agent). In the…
(Encyclopedia) Uslar Pietri, ArturoUslar Pietri, Arturoärt&oomacr;ˈrō &oomacr;sˈlär pyāˈtrē [key], 1906–2001, Venezuelan novelist and essayist. Uslar Pietri is considered one of the most…
(Encyclopedia) Ross, Alexander, 1783–1856, Canadian fur trader and pioneer, b. Scotland. He went to Canada in 1805, taught school in Upper Canada, and in 1810 left for Oregon as a clerk in John Jacob…
(Encyclopedia) Permian periodPermian periodpûrˈmēən [key] [from Perm, Russia], sixth and last period of the Paleozoic era (see Geologic Timescale, tablegeologic timescale, table) from 250 to 290…
The lightness or darkness of a color is called its value.
You can find the values of a color by making its tints and shades.
Tints are light values that are made by mixing a color with white. For…
FOREST OF KELPTYPES OF SEAWEEDALGAL OVERKILLPHYTOPLANKTONFIND OUT MOREAlgae are simple organisms that make food from sunlight by photosynthesis, but lack the roots, stems, and leaves of proper…
(Encyclopedia) Erythraean SeaErythraean Seaĕrĭthrēˈən [key], name of unclear origin anciently applied to the Indian Ocean, later to the Arabian Gulf, and finally to the Red Sea.
(Encyclopedia) jasper, opaque, impure cryptocrystalline quartz, usually red, but also yellow, green, and grayish blue. It is used as a gem. Ribbon jasper has the colors in stripes.
(Encyclopedia) bloodstone or heliotrope, green chalcedony spotted with red, used as a gem stone. It is found in India, the United States, Brazil, and Australia.
(Encyclopedia) Sherman, city (1990 pop. 31,601), seat of Grayson co., N Tex., near the Red River; inc. 1858. Originally on a stagecoach route, it is a highway and railroad junction. Manufactures…
