Part 4422

<p><b>2.</b> <def>Menstrual flux; catamenia; menses.</def> <mark>[Obs.]</mark>

<p><b>3.</b> <fld>(Min.)</fld> <def>See <er>Fluorite</er>.</def>

<h1>Fluor albus</h1> <Xpage=575>

<hw>Flu"or albus</hw> <tt>(?)</tt>. <ety>[L., white flow.]</ety> <fld>(Med.)</fld> <def>The whites; leucorrh\'91a.</def>

<h1>Fluoranthene</h1> <Xpage=575>

<hw>Flu`or*an"thene</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[<ets>Fluor</ets>ene + <ets>anth</ets>ra<?/ene.]</ety> <fld>(Chem.)</fld> <def>A white crystalline hydrocarbon C<?/H<?/, of a complex structure, found as one ingrdient of the higher boiling portion of coal tar.</def>

<h1>Fluorated</h1> <Xpage=575>

<hw>Flu"or*a`ted</hw> <tt>(?)</tt>, <tt>a.</tt> <fld>(Chem.)</fld> <def>Combined with fluorine; subjected to the action of fluoride.</def> <mark>[R.]</mark>

<h1>Fluorene</h1> <Xpage=575>

<hw>Flu`or*ene</hw> <tt>(?)</tt>, <tt>n.</tt> <fld>(Chem.)</fld> <def>A colorless, crystalline hydrocarbon, <chform>C13H10</chform> having a beautiful violet <i>fluorescence</i>; whence its name. It occurs in the higher boiling products of coal tar, and is obtained artificially.</def>

<h1>Fluorescein</h1> <Xpage=575>

<hw>Flu`o*res"ce*in</hw> <tt>(?)</tt>, <tt>n.</tt> <fld>(Chem.)</fld> <def>A yellowish red, crystalline substance, <chform>C20H12O5</chform>, produced by heating together phthalic anhydride and resorcin; -- so called, from the very brilliant yellowish green <i>fluorescence</i> of its alkaline solutions. It has acid properties, and its salts of the alkalies are known to the trade under the name of <i>uranin</i>.</def>

<h1>Fluorescence</h1> <Xpage=575>

<hw>Flu`o*res"cence</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[From <er>Fluor</er>.]</ety> <fld>(Opt.)</fld> <def>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.</def>

<i>Stockes.</i>

<h1>Fluorescent</h1> <Xpage=575>

<hw>Flu`o*res"cent</hw> <tt>(?)</tt>, <tt>a.</tt> <def>Having the property of fluorescence.</def>

<h1>Fluorescin</h1> <Xpage=575>

<hw>Flu`o*res"cin</hw> <tt>(?)</tt>, <tt>n.</tt> <fld>(Chem.)</fld> <def>A colorless, amorphous substance which is produced by the reduction of fluoresce\'8bn, and from which the latter may be formed by oxidation.</def>

<h1>Fluoric</h1> <Xpage=575>

<hw>Flu*or"ic</hw> <tt>(?)</tt>, <tt>a.</tt> <ety>[Cf. F. <ets>fluorique</ets>.]</ety> <fld>(Chem.)</fld> <def>Pertaining to, obtained from, or containing, fluorine.</def>

<h1>Fluoride</h1> <Xpage=575>

<hw>Flu"or*ide</hw> <tt>(? &or; ?; 104)</tt>, <tt>n.</tt> <ety>[Cf. F. <ets>fluoride</ets>.]</ety> <fld>(Chem.)</fld> <def>A binary compound of fluorine with another element or radical.</def>

<cs><col>Calcium fluoride</col> <fld>(Min.)</fld>, <cd>fluorite, <chform>CaF2</chform>. See <er>Fluorite</er>.</cd></cs>

<h1>Fluorine</h1> <Xpage=575>

<hw>Flu"or*ine</hw> <tt>(? &or; ?; 104)</tt>, <tt>n.</tt> <ety>[NL. <ets>fluorina</ets>: cf. G. <ets>fluorin</ets>, F. <ets>fluorine</ets>. So called from its occurrence in the mineral <ets>fluorite</ets>.]</ety> <fld>(Chem.)</fld> <def>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.</def>

<note>&hand; <i>Fluorine</i> unites with hydrogen to form hydrofluoric acid, which is the agent employed in etching glass. It occurs naturally, principally combined as calcium fluoride in <i>fluorite</i>, and as a double fluoride of aluminium and sodium in <i>cryolite</i>.</note>

<h1>Fluorite</h1> <Xpage=575>