black alkali

black alkali
Alkali soil Alkali soil Any one of various soils found in arid and semiarid regions, containing an unusual amount of soluble mineral salts which effloresce in the form of a powder or crust (usually white) in dry weather following rains or irrigation. The basis of these salts is mainly soda with a smaller amount of potash, and usually a little lime and magnesia. Two main classes of alkali are commonly distinguished: {black alkali}, which may be any alkaline carbonate, but which practically consists of sodium carbonate (sal soda), which is highly corrosive and destructive to vegetation; and {white alkali}, characterized by the presence of sodium sulphate (Glauber's salt), which is less injurious to vegetation. Black alkali is so called because water containing it dissolves humus, forming a dark-colored solution which, when it collects in puddles and evaporates, produces characteristic black spots. [Webster 1913 Suppl.]

The Collaborative International Dictionary of English. 2000.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • black alkali — noun : alkali containing carbonates that dissolve organic matter and blacken soil or crusts : soil blackened by such alkali …   Useful english dictionary

  • Alkali soil — Any one of various soils found in arid and semiarid regions, containing an unusual amount of soluble mineral salts which effloresce in the form of a powder or crust (usually white) in dry weather following rains or irrigation. The basis of these… …   The Collaborative International Dictionary of English

  • Black, Joseph — ▪ British scientist Introduction born April 16, 1728, Bordeaux, France died Nov. 10, 1799, Edinburgh, Scot.  British chemist and physicist best known for the rediscovery of “fixed air” ( carbon dioxide), the concept of latent heat, and the… …   Universalium

  • white alkali — Alkali soil Alkali soil Any one of various soils found in arid and semiarid regions, containing an unusual amount of soluble mineral salts which effloresce in the form of a powder or crust (usually white) in dry weather following rains or… …   The Collaborative International Dictionary of English

  • Black-necked Stilt — Taxobox name = Black necked Stilt image width = 230px image caption = Adult female at Morro Creek mouth, California status = LC status system = IUCN3.1 regnum = Animalia phylum = Chordata classis = Aves subclassis = Neornithes infraclassis =… …   Wikipedia

  • black death — Synonyms and related words: African lethargy, Asiatic cholera, Chagres fever, German measles, Haverhill fever, acute articular rheumatism, ague, alkali disease, ambulatory plague, amebiasis, amebic dysentery, anthrax, bacillary dysentery, bastard …   Moby Thesaurus

  • Black Rock Desert — ▪ region, Nevada, United States       arid region of lava beds and alkali flats composing part of the Basin and Range Province and lying in Humboldt and Pershing counties of northwestern Nevada, U.S. With an area of about 1,000 square miles… …   Universalium

  • black flux — noun metallurgy : a reducing flux composed of powdered carbon and alkali metal carbonate * * * Metall. a reducing flux consisting of finely divided carbon and potassium carbonate …   Useful english dictionary

  • black stock — noun : the dark colored material that in papermaking is discharged from a digester at the end of an alkaline cook of wood chips and contains the fiber, the alkali, and about half the weight of the wood in solution …   Useful english dictionary

  • Fixed alkali — Fixed Fixed (f[i^]kst), a. 1. Securely placed or fastened; settled; established; firm; imovable; unalterable. [1913 Webster] 2. (Chem.) Stable; non volatile. [1913 Webster] {Fixed air} (Old Chem.), carbonic acid or carbon dioxide; so called by Dr …   The Collaborative International Dictionary of English

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”