PEARL n.
A shelly concretion, usually rounded, and having a brilliant luster, with varying tints, found in the mantle, or between the mantle and shell, of certain bivalve mollusks, especially in the pearl oysters and river mussels, and sometimes in certain univalves. It is usually due to a secretion of shelly substance around s…
PETROLEUM n.
ists of a complex mixture of various hydrocarbons, largely of the methane series, but may vary much in appearance, composition, and properties. It is refined by distillation, and the products include kerosene, benzine, gasoline, paraffin, etc. Petroleum spirit, a volatile liquid obtained in the distillation of crude pe…
PISTIL n.
The seed-bearing organ of a flower. It consists of an ovary, containing the ovules or rudimentary seeds, and a stigma, which is commonly raised on an elongated portion called a style. When composed of one carpel a pistil is simple; when composed of several, it is compound. See Illust. of Flower, and Ovary.…