FLUORESCEIN n.
A yellowish red, crystalline substance, C20H12O5, produced by heating together phthalic anhydride and resorcin; -- so called, from the very brilliant yellowish green fluorescence of its alkaline solutions. It has acid properties, and its salts of the alkalies are known to the trade under the name of uranin.…
FLUORITE n.
Calcium fluoride, a mineral of many different colors, white, yellow, purple, green, red, etc., often very beautiful, crystallizing commonly in cubes with perfect octahedral cleavage; also massive. It is used as a flux. Some varieties are used for ornamental vessels. Also called fluor spar, or simply fluor.…
FLY AMANITA; FLY FUNGUS n.
nous mushroom (Amanita muscaria, syn. Agaricus muscarius), having usually a bright red or yellowish cap covered with irregular white spots. It has a distinct volva at the base, generally an upper ring on the stalk, and white spores. Called also fly agaric, deadly amanita.
FOUR-O'CLOCK n. 2 definitions
he warmer parts of America. The common four- o'clock is M. Jalapa. Its flowers are white, yellow, and red, and open toward sunset, or earlier in cloudy weather; hence the name. It is also called marvel of Peru, and afternoon lady.
FRANGULIC; FRANGULINIC a.
frangulin, or a species (Rhamnus Frangula) of the buckthorn. Frangulinic acid (Chem.), a yellow crystalline substance, resembling alizarin, and obtained by the decomposition of frangulin.