Vocabulary : Fluorescence to Fluoroscopy

Fluorescence : That property which some transparent bodies have of producing at their surface, or within their substance, light different in color from the mass of the material, as when green crystals of fluor spar afford blue reflections. It is due not to the difference in the color of a distinct surface layer, but to the power which the substance has of modifying the light incident upon it. The light emitted by fluorescent substances is in general of lower refrangibility than the incident light. ;; A property possessed by fluor spar, uranium glass, sulphide of calcium, and many other substances, of glowing without appreciable rise of temperature when exposed to light or to ultra-violet rays, cathode rays, X rays, etc.
Fluorescent : Having the property of fluorescence.
Fluorescin : A colorless, amorphous substance which is produced by the reduction of fluorescein, and from which the latter may be formed by oxidation.
Fluoric : Pertaining to, obtained from, or containing, fluorine.
Fluoride : A binary compound of fluorine with another element or radical.

Fluorine : A non-metallic, gaseous element, strongly acid or negative, or associated with chlorine, bromine, and iodine, in the halogen group of which it is the first member. It always occurs combined, is very active chemically, and possesses such an avidity for most elements, and silicon especially, that it can neither be prepared nor kept in glass vessels. If set free it immediately attacks the containing material, so that it was not isolated until 1886. It is a pungent, corrosive, colorless gas. Symbol F. Atomic weight 19.
Fluorite : 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.
Fluoroid : A tetrahexahedron; -- so called because it is a common form of fluorite.
Fluoroscope : An instrument for observing or exhibiting fluorescence. ;; A fluorescent screen, with hood to protect the eyes, used for observing the shadows cast by objects placed in the path of the X rays.
Fluoroscopy : Examination of an object, as the human body, by exposing it to the X rays and observing the shadow cast upon a fluorescent screen; cryptoscopy.