LIGNINE. 



LIME 



Magnified 450 diameters. 

 Elastic fibres from the inner part of the fascia lata, human ; densely interwoven and forming an elastic membrane. 



BIBL. Kolliker, Mik. An. i. ; Henle, All- 

 gem. An. ; Bonders, Mulder's Phys. Chem. ; 

 Frey, Hist. 240. 



LIGNINE. A modified condition of 

 cellulose is obtained from old wood-cells, 

 and called by this name. It differs in its 

 reactions from pure cellulose, being coloured 

 yellow by sulphuric acid and iodine; but 

 after boiling in nitric acid and washing, 

 tincture of iodine and water give it a blue 

 colour. See SECONDARY DEPOSITS. 



UMBORHLE. A family of Angiocar- 

 pous or closed-fruited Lichens characterized 

 by rounded apothecia closed in by a carbo- 

 naceous special perithecium, finally bursting 

 in various ways, containing a somewhat 

 waxy nucleus, which grows hard. 



British genera : Pyrenothea, Strigida. 



LIME, SALTS OF. 



Carbonate of lime. This substance is well 

 known as forming chalk, marble, &c., and as 

 occurring in hard animal structures, as bone, 

 shell, &c. It is not unf requently met with 

 in the form of granules as a component of 

 various animal secretions, as the urine, &c. 

 In this liquid, it sometimes, but rarely, also 

 occurs in little spheres or disks, consisting 

 of groups of radiating needles. This we 

 first found to be the case in human urine 

 (PI. 13. fig. 8); but it was subsequently 

 detected in that of herbivorous animals, as 

 the cow and the horse (PI. 13. fig. 7), in 

 which its occurrence is common. It is also 



a component of otolithes, in which it exists 

 either as granules or minute prisms, often 

 with six sides and trilateral summits. From 

 river- and spring-water it is usually deposited 

 in irregular and imperfect forms (PI. 13. 

 fig. 6), all of which consist of grouped nee- 

 dles. Sometimes it assumes the rhombohe- 

 dral form, as in the shell of the oyster (PI. 45. 

 fig. 10) and frequently in ch.emica.1 solutions. 

 When treated with a dilute acid, after having 

 been thoroughly washed in a watch-glass, 

 it is dissolved with effervescence from the 

 escape of carbonic acid gas. During the 

 solution it first becomes more transparent, 

 exhibiting the internal crystalline structure, 

 and frequently a concentric or nuclear ap- 

 pearance, which finally disappears. When 

 derived from animal secretion^, it leaves 

 undissolved an organic cast of the original, 

 provided the acid be not too strong, or its 

 action too long continued. If the number 

 and size of the minute bodies be relatively 

 very small in nroportion to the amount of 

 water, on adding the acid, effervescence 

 will not occur, the water holding in solution 

 the carbonic acid evolved. The presence 

 of the lime may be tested in the ordinary 

 way, by the addition of oxalate of ammonia, 

 when the precipitate is insoluble in acetic 

 acid, or by adding dilute sulphuric acid, 

 when crystalline needles of the sulphate of 

 lime (PI. 10. fig. 16) are formed. 



The spheres or disks naturally occurring 



