FIB 



FIB 



FEVERFEW. See MATBICARIA. 

 FEU1LLEA, in botany, so called in ho- 

 nour of Louis Feuillee, a genus of the 

 Dioecia Pentandria class and order. Na- 

 tural order of Cucurbitacese. Essential 

 character : male, calyx five-cleft ; corolla 

 five-cleft ; stamens five ; nectary five con- 

 verging filaments : female, calyx five- 

 cleft ; styles three ; pome hard, three- 

 celled, corticose. There are two spe- 

 cies. 



FIBER, the beaver, in zoology, is 

 made, by Linnaeus, a species of castor. 

 See CASTOR. 



FIBRE, in anatomy, a perfectly simple 

 body, or at least as simple as any thing 

 irt the human structure ; being fine and. 

 slender like a thread, and serving to 

 form other parts. Hence some fibres are 

 hard, as the bony ones ; ad others soft, 

 as those destined for the formation of all 

 the other parts. See ANATOMY. 



FIBRES,/ori6fe union of. The strength 

 of cordage and of other substances which 

 are employed in the communication of 

 motion, where flexibility is required, as 

 well as the utility of other flexible ma- 

 terials, depends principally upon the la- 

 teral adhesion produced by twisting, or 

 by the intermixture of fibres. The me- 

 chanism of simple spinning is easily un- 

 derstood ; care is taken, where the hand 

 is employed, to intermix the fibres suffi- 

 ciently, and to engage their extremities 

 as much as possible in the centre ; for if 

 any fibre were wholly external to the 

 rest, it could not be retained in the yarn. 

 See ROPE, SPIXNISTG, &c. 



FIBRIN. If a quantity of blood, newly 

 drawn from an animal, be allowed to re- 

 main at rest for some time, a thick red 

 clot, gradually forms in it, and subsides. 

 Separate this clot from the rest of the 

 blood, put it into a linen cloth, and wash 

 it repeatedly in water till it ceases to give 

 out any colour or taste to the liquid ; the 

 substance whidh remains after this pro- 

 cess is denominated fibrin. It has been 

 long known to physicians, under the 

 name of the fibrous part of the blood ; but 

 has not till lately been accurately describ- 

 ed. It may be procured also from the 

 muscles of animals. 



Fibrin is of a white colour, has no taste 

 nor smell, and is not soluble in water nor 

 in alcohol. It undergoes no change, 

 though kept exposed to the action of the 

 air ; neither does it alter speedily, though 

 kept covered with water. When expos- 

 ed to heat, it contracts very suddenly, 



and moves like a bit of horn, exhaling at 

 the same time the smell of burning fea- 

 thers. In a stronger heat it melts. When 

 exposed to destructive distillation, it 

 yields water, carbonate of ammonia, a 

 thick, heavy, fetid oil, traces of acetic 

 acid, carbonic acid, and carburetted hy- 

 drogen gas. The charcoal, as Hatchett 

 ascertained, is more copious than that 

 left by gelatine or albumen. It is very 

 difficult to incinerate, owing 1 to the pre- 

 sence of phosphate of soda, and some 

 phosphate of lime, which form a glassy 

 coat on the surface. A considerable pro- 

 portion of carbonate of lime also remains 

 after th,e incineration of the charcoal. 



Acids dissolve fibrin with considerable 

 facility. Sulphuric acid gives it a deep 

 brown colour", charcoal is precipitated, 

 and acetic acid formed. Muriatic acid dis- 

 solves it, and forms with it a green-colour- 

 ed jelly. The acetic, citric, oxalic, and tar- 

 taric acids also dissolve it by the assistance 

 of heat; andt he solutions, when concen- 

 trated, assume the appearance of jelly. 

 Alkalies precipitate the fibrin from acids 

 in flakes, soluble in fiot water, and re- 

 sembling gelatine in its properties. 



From the recent experiments of Four, 

 croy and Vauquelin on the muscular fi- 

 bres of animals, there can be little doubt 

 that fibrin, when treated with hot nitric. 

 acid, undergoes a suit of changes. 1. It is 

 converted into a yellow matter, which 

 still possesses the fibrous texture of fibrin, 

 It has the property of converting vegeta- 

 ble blues to red, has a bitter taste, is but 

 little soluble in water, and is insoluble in 

 Alcohol. It combines with alkalies, de- 

 composes their carbonates, unites to oils, 

 and gives them rancidity and acid proper- 

 ties. To this substance, Fourcroy and Van 

 queline have given the name of yellow 

 acid. 2. By the farther action of the nitric 

 acid, this yellow matter becomes more 

 soluble, acquires a reddish tinge, and 

 seems to become soluble in alcohol. 3, 

 The last state into which it is brought by 

 nitric acid seem's to be that species of bit- 

 ter principle/which crystallizes and deto- 

 nates when combined with ammonia. 



The alkalies, when diluted, have but 

 little effect upon fibrin; but when concen- 

 trated potash or soda is boiled upon it, a 

 complete solution is obtained, of a deep 

 brown colour, possessing the properties 

 of soap. During the solution ammonia is 

 disengaged. When the solution is saturat- 

 ed with muriatic acid, a precipitate is ob- 

 tained similar to Uiat from animal soap, 



