FUN 



FUS 



noting mercury, employed for percussion 

 caps, and obtained by dissolving mercury 

 in nitric acid, and pouring the solution 

 into alcohol; fulminating silver, prepared 

 by leaving oxide of silver for a day in a 

 strong solution of ammonia. 



FULMINA'TION {fulmen, a thunder- 

 bolt). The explosion which takes place 

 in chemical bodies by heat or friction. 



FULMI'NIC ACID {fulmen, a thunder- 

 bolt). A compound of cyanogen, cor- 

 responding in its ultimate composition 

 with cyanic acid, and exploding when 

 heated, rubbed, or struck. 



FUMA'RIC ACID. A monobasic acid, 

 existing in fumaria or fumitory, and pro- 

 duced artificially by heating malic acid. 



FUMING LIQUOR {fumus, smoke). 

 A chemical mixture, whicl^ emits fumes 

 or vapour on exposure to the air. Boyle's 

 fuming liquor is the protosulphuret of 

 ammonium ; Cadet's is procured by dis- 

 tilling acetate of potash and arsenious 

 acid ; Libavius's is the anhydrous bichlo- 

 ride of tin. 



FUNCTION [fungor, to discharge an 

 office). The office of an organ in the ani- 

 mal or vegetable economy, as of the heart 

 in circulation, of the leaf in respiration. 

 Animal functions are those which relate 

 to the external world, as the senses, 

 voluntary motions, &c. Vital functions 

 are those immediately necessary to life, 

 as those of the heart, the brain, the lungs, 

 which have been termed the tripod of 

 life. 



FUNCTION (in Analysis). A term 

 applied to an algebraical expression in 

 which a certain letter or quantity is com- 

 pounded with other letters or quantities : 

 the expression is then said to be di func- 

 tion of that letter or quantity ; thus a+x 

 and o2-fx* are, both, functions of x ; the 

 circumference of a circle is the function 

 of the radius. 



Functions, calculus of. That branch 

 of analysis which investigates the form 

 of a function, and not its value in any 

 particular case, nor the conditions under 

 which it may have a particular value. 

 Thus, the calculus of functions may be 

 considered as similarly related to alge- 

 bra, as algebra is to common arithmetic. 



FUNDAMENTAL BASE. The root, 

 or lowest note of a musical chord, found 

 by inverting its notes so as to set them 

 in thirds above this root. 



FUNGACEiE. The mushroom tribe 

 of Cellular or Acotyledonous plants. 

 Plants consisting of a congeries of cel- 

 lules, chiefly growing upon decayed sub- 

 145 



stances. Sporules lying either loose 

 among the tissue, or enclosed in mem- 

 branous cases called sporidia. 



FU'NGATES. The saline compounds 

 of a peculiar acid extracted from mush- 

 rooms. 



FUNGIC ACID. An acid procured 

 from several species of fxingus, by ex- 

 pressing their juice, boiling it, forming an 

 extract, and treating it with alcohol. 



FUNGIN. A whitish substance form- 

 ing the base of fungi. 



FUNI'CULAR MACHINE {funiculus, 

 a little rope). A mechanical contrivance 

 by which bodies are supported by means 

 of force applied to an assemblage of 

 ropes, as in bracing the sails of ships. 



FUNI'CULUS (dim. of funis, a cord). 

 The little cord, by which the ovule of 

 plants is attached to the placenta, of 

 which, indeed, it is a prolongation. 



FURNACE. A fire-place used for the 

 purposes of fusion, distillation, sublima- 

 tion, and the oxidation and deoxidation, 

 or reduction of metals. It is termed eva- 

 poratory, when employed to reduce sub- 

 stances into vapour by heat; reverbera- 

 tory, when so constructed as to prevent 

 the flame from rising ; and forge, when 

 the current of air is determined by bel- 

 lows. 



FUSCIN {fuscus, tawny). A brownish 

 matter obtained from empyreumatic ani- 

 mal oil. 



FU'SCITE {fuscus, tawny). An opaque 

 greyish or greenish-black mineral, found 

 in Norway, in rolled masses of granular 

 quartz. 



FUSELOL. An oily liquor obtained 

 from alcohol, also termed oil of grain, 

 and, hypothetically, hydrate of amyl. 



FUSIBI'LITY. The property by which 

 solid bodies are capable of assuming 

 the fluid state on the application of 

 heat. 



FU'SIBLE METAL. An alloy of eight 

 parts of bismuth, five of lead, and three 

 of tin. This compound, sometimes called 

 Newton's, from the name of its disco- 

 verer, melts at the heat of boiling water, 

 and may be fused over a candle in a piece 

 of stiflT paper, without burning the paper. 

 Hose's fusible alloy is a similar com- 

 pound. 



FU'SIFORM {fusus, a spindle, forma, 

 likeness). Spindle-shaped; thickest in 

 the middle and tapering to the extremi- 

 ties, as the cells composing woody fibre, 

 the flesliy part of the long radish, &c. 



FU'SIN^. Spindle-shells; a sub- 

 family of the TurbinellidcBy or Turnip- 

 H 



