LEYDEN 



108 



IIGNONE 



Leyden jar, (li'den). [Leyden in Holland.] 

 A glass jar coated partly, both outside and 

 inside, with tin-foil; when electrified it can 

 be discharged by connecting the coatings, 

 when a shock or spark is given. L. battery: 

 a number of such jars connected by wires. 



Lias, (li'as). Beds of limestone, marl, and 

 clay, mostly of marine formation, remarkable 

 for fossil remains of large lizard-like animals ; 

 a sub-division of Jurassic, q. v. v. Secondary 

 formations. Sometimes called Gryphite 

 limestone. 



Liassic, (H-as'sik). [Lias, q.v.] Belonging 

 or related to the Lias, q.v. 



Libavius, liquor of= Bichloride of tin. 



Libellula, (lib-el'lu-la). [L. libellus, little 

 book.] Dragon-fly: an insect belonging to 

 Libellulidse, q. v. ; also called horse-stinger. 



Libellulidffl, (lib-el-lull-de). [Libellula, q.v. ; 

 Gk. cidos, form.]=Dragon-flies: carnivorous 

 insects, forming a division of Neuroptera, 

 brillantly coloured; males usually larger 

 than females. 



Liber, (li'ber). [The Latin word.] The inner 

 bark of fine woody fibres; also called Endo- 

 phlseum. 



Liberatrix, (li-ber-a'triks). [The Latin name. ] 

 No 125 of the Minor Planets. 



Libra, (li'bra). [The Latin name.]=Balance: 

 a constellation of 

 the Zodiac. 2. The 

 7th sign of the 

 Zodiac, now con- 

 tains the constel- 

 lation Virgo. 



Libration, (11-bra'- 

 shun). [L. libra, 

 balance. ] = Evec - 

 tion: an apparent Libra, 



displacement of any heavenly body, owing 

 to its motion. 



Lice, (lis). Wingless insects, belonging to 

 Hemiptera; also considered as belonging to 

 Aptera. Wood L. = Isopoda. 



Lichanotus=Indri: an animal belonging to 

 Lemuroidea: found in Madagascar. 



Lichen, (li'ken). [The Latin name.] v. 

 Lichenales. 



Lichenales, ( li-ke-na'lez ). [Lichen, q.v.] 

 Perennial flowerless plants of cellular 

 tissue, multiplied by spores, found on the 

 surface of rocks, trees, &c., growing only in 

 light; combining the vegetation of Algales 

 with the fruit of Fungales, forming a 

 division of Thallogens, q.v. 



Lichenic, (li-ken'ik). [Lichen, q.v.] Relating 

 to Lichens. L. acid=Fumaric acid, q.v. 



Lichenin, (li'ke-nin). [Lichen, q.v.] C 6 H 10 O 6 : 

 a substance obtained from Iceland moss. 



Lichens, (ll'kenzj). [Lichen, q.v.] Plants 

 belonging to Lichenales, q.v. Cudbear L. 

 =Lecanora tartarea. Dog L. = Peltidea 

 canina. Jelly .L. =Collemaceae. Letter L.= 

 Graphidaceae. Lung-wort Z/.=Sticta pul- 

 monaria. Rockhair /y.=Alectoria jubata. 

 Stone Zr.=Parmelia parietina. Tripe de 

 Roche L. =;Gyrophora=Lecanora esculenta. 

 Written I/.=Opegrapha scripta. 



Lichens, Colouring matters, &c., obtained 



from: Archil, Erythrin, Evernic acid, Gyro- 

 phoric acid, Lecanoric acid, Litmus, Orcin, 

 &c. 



Lichtenberg's figures. A mixture of sulphur 

 and red lead becomes electrified (the sulphur 

 negatively, the red lead positively) if such a 

 mixture be spread over a cake of resin on 

 which lines have been traced by a positively 

 electrified substance, and other lines by a 

 negatively electrified one, and figures are 

 formed by the separation of the sulphur and 

 red lead. 



Licking insects=Hymenoptera. v. Insects. 



Lieberkuhn, glands of, In the walls of the 

 intestines. 



Liebig, (le'big). [Prof. Liebig.] L.'s classifi- 

 cation 1. Of crops: according to the alkaline, 

 flinty, or lime-like character of their ashes. 

 2. Of foods: according to their support of 

 nutrition or respiration. L.'s condenser: a 

 retort in the head of which water is boiled, 

 while the neck is kept cool by a stream of 

 cold water. L.'s theory of fermentation. 

 v. Fermentation. 



Ligament, (ligVment). [Ligamentum, the 

 Latin word.] Bauds of fibrous tissue con- 

 necting bones, &c. cf. Tendon. 



Light, (lit). [Lyht, the A.-S. word.] A 

 variety of molecular motion; a form of 

 energy; of which our eyes only can take 

 cognizance, and which gives us the per- 

 ception of form and colour. Sources of L. ; 

 the sun, stars, chemical combination, elec- 

 tricity, &c. Homogeneous L.=Monochro- 

 matic L. = Light of one colour only. Electric 

 L., v. Electric. Chemical action of L.= 

 Actinism, v. Photography. Diffraction of 

 L., v. Diffraction. Dispersion of L., v. 

 Spectrum. Measurement o/l/.=Photometry. 

 Polarisation of L., v. Polarisation. L. mill 

 =Radiometer, q.v. 



Light-balls. Projectiles, filled with combus- 

 tibles that burn with a bright flame for 

 several minutes: used in warfare to see by. 



Lightning, (lit'ning). [Light, q.v.] A dis- 

 charge of atmospheric electricity. L. bridge: 

 a short interval between two wires, which a 

 current of great tension will cross and so 

 pass away from delicate apparatus. L. con- 

 ductor: a metallic rod or band, fixed to a 

 ship, house, &c., and projecting above the 

 highest part, intended to carry off lightning 

 harmlessly by conducting it to the ground. 

 L. spectrum: the spectrum of a flash of 

 lightning. L. tubes= Fulgurites, q.v. 



Lights. Artificial L. : obtained by burning 

 coal-gas, candles, oil, &c., v. Drummond L. 

 and Electric L. Dead L., v. Dead light. 

 Northern L., v. Aurora borealis. Southern 

 L., v. Aurora australis. 



Lignin, (lig'nin). [L. lignum, wood.] 1.= 

 Cellulose: one of the constituents of wood. 

 2. A compound substance encrusting the 

 cellulose framework of plant tissues. 



Lignite, (lig'nit). lL.'lignum, wood.]=Brown 

 coal: coal retaining its woody structure= 

 Forest bed. 



Lignone, (lig'non)=Xylite: a volatile liquid 

 obtained from wood spirit. 



