FIR 



FLA 



appear as a point, a plane as a straight 

 line, and a solid as a simple surface. 



FIGURE OF A SYLLOGISM. A 

 logical expression, denoting the situation 

 of the middle term with respect to the 

 extremes of the conclusion (i. e. the 

 major and the minor term). The figures 

 of reasoning are only different forms of 

 stating it. 



FI'LAMENT {filamentum, a little 

 thread). The thread-like portion of the 

 stamen, which supports the anther. 



FI'LICES {filix, a fern). The Fern 

 tribe of Acotyledonous plants. Leafy 

 plants, producing a rhizome; fronds 

 simple or variously divided ; flowerless ; 

 reproductive organs consisting of thecce 

 or semi-transparent cases appearing on 

 the back or margin of the fronds. 



FILITE'L^ {filum, a thread, tela, a 

 web). A family of Spiders, remarkable 

 for the long threads of silk which they 

 spread about in the places where they 

 prowl in quest of prey. 



FILTRATION. The process of «^ram- 

 ing a liquid through z, filter, or separating 

 it mechanically from the particles which 

 are mixed with it. Filters are usually 

 made of unsized or blotting paper. 



FFMBRIATED {fimbria, a fringe). 

 Fringed ; having the margin bordered by 

 filiform appendages; a term applied to 

 the thin, elevated, fin-like processes, 

 belonging to many of the murices, and 

 sometimes placed round the aperture of 

 cyclostomous land-shells. 



Fl'ORITE. Pearl sinter; a volcanic 

 production, chiefly silica, in a stalactitic 

 form. 



FIRE-BALLS. Bolides, or fiery me- 

 teors ; luminous bodies, which suddenly 

 appear at a considerable height in the 

 atmosphere, and shoot through the 

 heavens with great velocity, sometimes 

 accompanied with the fall of an aerolite. 



FIRE DAMP. A gas evolved in coal 

 mines, consisting almost entirely of light 

 carburetted hydrogen. 



FIRE ENGINE. The fire engine is a 

 modification of the forcing pump. It 

 consists of two such pumps, the pistons 

 of which are moved by a lever with equal 

 arms, having a common fulcrum. When 

 one piston is descending, the other is 

 ascending. The machine acts precisely 

 like the forcing pump, only that its 

 power is doubled by having two pistons 

 instead of one. 



FIRE, GREEK. An inflammable 

 composition employed in the wars of the 

 middle ages, supposed to consist princi- 

 137 



pally of naphtha mingled with pitch and 

 sulphur. 



FISH. The name applied to a class 

 of animals occupying the lowest station 

 of the four great divisions of the section 

 Vertebrata. They are distinguished, 

 with reference to the substance of their 

 skeleton, into the osseous and the carti- 

 laginous or chondropterygious. See 

 Ichthyology. 



FISSI'PAROUS ifissus, cleft, pario, 

 to bring forth). A designation of that 

 mode of propagation, which takes place 

 by spontaneous division of the body of 

 the parent into two or more parts, each 

 part, when separated, becoming a dis- 

 tinct individual, as in the monad, vorti- 

 cella, &c. ; or by artificial division, as in 

 the hydra, planaria, &c. ; and in the 

 propagation of plants by slips. 



FISSIPE'NNiE ifissus, cleft, penna, 

 a wing). A family of Lepidopterous in- 

 sects, commonly called Plumed Moths, 

 and characterized by the division of the 

 membrane of the wings into branches or 

 rays, of which each pair has from two to 

 six. 



FISSIRO'STRES {fissus, cleft, ros- 

 trum, a bill). A group of the Insessores, 

 or Perching Birds, having a short, broad, 

 horizontally-depressed bill, so formed 

 that the gape of the mouth is extremely 

 wide. It comprises the swallows, goat- 

 suckers, bee-eaters, kingflshers, and 

 todies. 



Fl'STULOUS {fistula, a pipe). Cylin- 

 drical and hollow, as the stems of grasses, 

 of umbelliferous plants, &c. 



FIXED AIR. A name formerly given 

 by chemists to the air which was extri- 

 cated from lime, magnesia, and alkalies, 

 now called carbonic acid gas. 



FIXED SIGNS OF THE ZODIAC. 

 These are Taurus, Leo, Scorpio, and 

 Aquarius ; they are so called because 

 the season is considered to be more 

 settled when the sun passes through 

 these signs, than at any other times of 

 the year. 



FIXED STARS. Stars which do not 

 appear to change their relative situations, 

 as distinguished from planets and comets. 



FI'XITY. The property by which 

 bodies resist the action of heat, so as not 

 to rise in vapour, as the fixed, in contra- 

 distinction to the volatile oils ; or non- 

 metallic elements, which can neither be 

 fused nor volatilized, as carbon, silicon, 

 and boron. 



FLABE'LLIFORM {flabellum, a fan, 

 forma, likeness). Fan-shaped; plaited 



