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hardness

(Encyclopedia)hardness, property of matter commonly described as the resistance of a substance to being scratched by another substance. The degree of hardness is relative, different substances being compared with o...

decay of organic matter

(Encyclopedia)decay of organic matter or putrefaction, process whereby heterotrophic organisms, including some bacteria, fungi, saprophytic plants, and lower animals, utilize the remains of once-living tissue as a ...

ash, in chemistry

(Encyclopedia)ash, in chemistry, solid residue of combustion. The chemical composition of an ash depends on that of the substance burned. Wood ash contains metal carbonates (e.g., potassium carbonate) and oxides fo...

laxative

(Encyclopedia)laxative, drug or other substance used to stimulate the action of the intestines in eliminating waste from the body. The term laxative usually refers to a mild-acting substance; substances of increasi...

sediment

(Encyclopedia)sediment, mineral or organic particles that are deposited by the action of wind, water, or glacial ice. These sediments can eventually form sedimentary rocks (see rock). Sediments form sedimentary ...

serpentine

(Encyclopedia)serpentine sûrˈpəntēn, –tīn [key], hydrous silicate of magnesium. It occurs in crystalline form only as a pseudomorph having the form of some other mineral and is generally found in the form of...

fertilizer

(Encyclopedia)fertilizer, organic or inorganic material containing one or more of the nutrients—mainly nitrogen, phosphorus, and potassium, and other essential elements required for plant growth. Added to the soi...

diamond

(Encyclopedia)diamond, mineral, one of two crystalline forms of the element carbon (see allotropy), the hardest natural substance known, used as a gem and in industry. The discoveries of 1870–71 in South Africa...

ammonium sulfate

(Encyclopedia)ammonium sulfate, chemical compound, (NH4)2SO4, a colorless-to-gray, rhombohedral crystalline substance that occurs in nature as the mineral mascagnite. It is soluble in water and insoluble in alcohol...

Killarney

(Encyclopedia)Killarney, town (1991 pop. 7,274), Co. Kerry, SW Republic of Ireland. The town, which has mineral-water bottling, footwear, lace, hosiery, woolens, and ornamental ironwork industries, is also a touris...