423 



LIGNITE. 



LIGUSTRUM. 



430 



leaves of endive and of Aylantkw glanduloia, the trachese of the 

 Ituta, sapient um, films from the pith of oak-trees, cellulose from cow- 

 dung (the cow fed with meadow-grass), the internal tissue of the 

 leaves of Agave Americana, the skeleton of a wasp's nest, the perisperm 

 of the Phytelephat, extracted lichen, membranes of the C'hara, &c. 

 From these and various other substances, the purified cellulose always 

 gave a result approximating to the formula C 24 H 21 2l . It is thus 

 apparent that the proper tissue of all plants leaves a substance which 

 is identical for all of them, a substance which contains carbon and 

 the elements of water, which is isomeric with inulin, and therefore 

 easily convertible into starch and sugar; and that in its turn it may 

 easily be produced from dextrine [DEXTRINE ; STARCH], the change 

 consisting only in the loss or gain of the elements of water. It has 

 been shown by Von Baumhauer that sulphuric acid or diastase will 

 convert cellulose into dextrine. It is also by the same process con- 

 verted into starch. Hence it is concluded that the cellular substance 

 is closely allied to starch, dextrine, gum, and sugar, causing their 

 production in the vegetable kingdom, and no doubt being itself pro- 

 duced from one of them, namely, from dextrine. It is therefore of 

 great importance to the animal body. It explains the nourishing 

 power of those plants in which the incrustation of the cellulose is 

 prevented by artificial means, as of greens, endive, sea-kale, &c. The 

 cellulose of these plants, being easily converted into dextrine, may 

 fairly be reckoned amongst the substances which are most serviceable 

 in maintaining the vital functions of animals. 



Further, as cellulose exists ready formed in the youngest parts of 

 plants, it belongs, together with protein, to the first vegetable products 

 of the food of plants ; and, further, it follows that from cellulose, or 

 from vegetable substances similarly formed, especially from one soluble 

 in water, namely, dextrine, starch, gum, and sugar are occasionally 

 formed. In many parts of plants we find starch, especially in the 

 Lichens, which consist for the most part of cellulose. In many fruits 

 containing a large proportion of cellulose, there is much sugar. These 

 different substances may be produced from the same cellulose, simply 

 by a change in its physical character and a new chemical arrangement 

 of its constituents. On the other hand we observe that fleshy fruits, 

 from being sugary, become mealy when kept through the winter; 

 this being a converse change of sugar into cellulose. Hence, as Mulder 

 remarks, " we may consider the cellular plants as consisting chiefly of 

 cellulose and of protein-compounds; the vascular plants containing 

 in addition the incrusting or real woody matter. These together are 

 the most indispensable constituents of plants ; they are found every- 

 where and in all their organs. Cellulose is to plants what gelatin is 

 to animals ; they form together the cells in these two kingdoms. In 

 the cells both of plants and animals protein-compounds are either 

 deposited in solid particles or are dissolved in the liquids with which 

 their organs are permeated. In plants the cell-walls are thickened by 

 the woody matter ; in animals the cells contain fat and other sub- 

 stances ; in animals, as well as in plants, the cellular substance is the 

 chief agent in connecting all the other existing organs." 



Hohl and Schleiden have shown that the cellular membrane of many 

 parts of plants is coloured blue by iodine, just as if it contained starch. 

 This apparent identity of reaction would lead us to infer that cellu- 

 lose can often be modified as it were into starch, though still retaining 

 the appearance of cellular membrane. The similarity of the chemical 

 constitution of these two substances renders their conversion appa- 

 rently easy. For 1 eqiv. cellulose (C 24 H,, Oj,) = 2 eqiv. starch" (C al 

 H, OJ + 1 eqiv. water (H 0). Hence, by a separation of water and 

 a re-arrangement of the molecules, cellulose may be converted into 

 starch ; and conversely, by the absorption of water, starch may be con- 

 verted into cellulose. Cellulose is the basis of the substance called 

 Gun Cotton, which again on being dissolved in ether forms Collodion. 



(Mulder, Ctiemiitry of A nimal and Vegetable Physioloyy ; Gregory, 

 Organic Chemistry.) 



LIGNITE. Fossil wood carbonised to a certain degree, but retain- 

 ing distinctly its woody texture, is thus designated. A greater degree 

 of change constitutes C'annel and Common Coal, in which the original 

 structure of the constituent plants can only with difficulty be traced ; 

 a less change belongs to Peat. 



Dr. M'Culloch observes : " In its chemical properties Lignite holds 

 a station intermediate between peat and coal ; while among the varieties 

 a gradation in this respect may be traced ; the brown and more 

 organised kinds approaching very near to peat, while the more com- 

 pact kinds, such as jet, approximate to coal" (' On Rocks,' p. 636.) 



His synopsis of Lignite runs thus : 



A. Jet. Hard, compact, with pitchy lustre. 



B. Surturbrand. Less compact and more brittle than jet. 



C. Moor Coal of some authors. Friable. 



D. Bnvey Coal. Fibrous, the vegetable texture very apparent, colour 



brown or brownish-black. 

 . Cologne earth, earthy and pulverulent mass. The thickness said 



to be 50 feet. 

 F. Basaltic Coal. Of variable structure; some parts like wood, 



others like coal. 



Lignite often occurs in beds of considerable thickness and extent, 

 and supplies to particular districts a bad substitute for coal. It is often 



accompanied by iron pyrites (Alum Bay), lies in alternating series with 

 arenaceous and argillaceous beds, and is sometimes covered by fresh- 

 water limestone (Kiipfnach), and presents many analogies with coal ; 

 but in general Lignite is most plentiful in the tertiary strata, and Coal 

 among the older rocks of the secondary series. 



In the Isle of Wight (Alum Bay) Lignite beds (the wood coniferous) 

 occur amidst the sands and clays of the lower part of the (Eocene) 

 tertiary strata ; in a depression of the surface near Bovey Tracey, 

 Devon, a more considerable deposit of like nature occurs under 

 several alternating beds of clay and gravel of considerable thickness. 

 (De la Beche, ' Geol. Manual.') These deposits deserve attentive com- 

 parison with the peat moors of high and low situations in England, 

 with and without buried forests, with the Lignite Coal of the Sussex 

 Wealden, the Coal of the Yorkshire Oolites derived from Equiseta, and 

 the Coal of the older rocks in which coniferous wood appears an 

 abundant ingredient. 



According to Brongniart (' Tableau des Terrains'), at least three 

 deposits of Lignite of different geological ages may be distinguished 

 in the series of tertiary strata, namely, the Lignite of Switzerland, 

 of Mont Rouge, and of Aisne (all of Eocene date, according to Lyell's 

 classification). Among the secondary strata one deposit is noticed 

 by Brongniart, namely, in the Isle of Aix, belonging to the Lower 

 Greensand, and occurrences of less importance in the Wealden of 

 Sussex, the Kimmeridge Clay, Lias, and Gres Bigarrd. Hardly any of 

 the clays of the Cretaceous or Oolitic formations are deficient of jet, 

 which sometimes forms considerable floors (as near Whitby), but 

 generally lies in small portions. 



The plants occurring in all these' deposits are terrestrial ; in the 

 Swiss and French Lignites there are remains of palms ; in the Meissner 

 there are coniferous woods. Mammalia occur, especially in the Swiss 

 Lignites, at Kiipfnach, near Zurich, where Mastodon angustidens, 

 M. Turicewe, Beaver, Rhinoceros tichorhinus, and other remains are 

 mentioned by different writers. One of the most characteristic genera 

 of the animals found in Lignite (Tuscany, Styria) is the Anthraco- 

 therium. 



LIGULATE FLOWERS are such as have a monopetalous corolla 

 slit on one side, and opened flat, as in the Dandelion Lilac. 



LIGURITE, a Mineral. Its primary form is an oblique rhombic 

 prism. Colour apple-green. Streak grayish-white. Fracture uneven. 

 Hardness above 5'0. Lustre of the surface of fracture btween vitreous 

 and resinous. Transparent and translucent. Specific gravity 3-49. 

 It is found on the banks of the Stura, in the Apennines of Liguria. 

 Its analysis, by Viviani, gives 



Silica 57-45 



Alumina 7'36 



Lime 25'30 



Magnesia 2-56 



Oxide of Iron . . . . . 3'00 



Oxide of Manganese . . . . 0-50 



9617 



LIGUSTRUM, a genus of Plants belonging to the natural order 

 Jaiminaceoe. It has a fleshy fruit, the berry containing two mem- 

 branous 1-seeded nuts. The calyx is short, tubular, and 4-toothed ; 

 the limb of the corolla 4-parted,and spreading; stamens two, wilh 

 short filaments. The species are shrubs or low trees, natives of Europe 

 and Asia. 



L. vvlgare, Common Privet, has elliptic lanceolate glabrous leaves ; 

 compound racemes; sweet-scented flowers, white at first, but soon 

 changing to a reddish-brown. The berries are dark purple, almost 

 black. It is a bushy sub-evergreen shrub, growing in hedges and 

 thicketr in Great Britain, and native of the south-west of England. 

 This plant was formerly called Prim, or Primwort, from its being used 

 for verdant sculptures, or topiary-work, and for primly cut hedges. 

 The common English name Privet seems to have been given to it 

 from its being frequently planted to conceal private places. In Ger- 

 man, Dutch, Danish, and Swedish it is called Lignster ; in French, 

 Troene ; in Italian, Ligustro ; in Spanish, Alhena ; and in Portuguese, 

 Affeua. It is probably the Sirfptua of Theophraatus, ' Hist. Plant." 

 i. 14. In point of utility and ornament few shrubs exceed the privet. 

 Its chief use is to form hedges either for shelter or ornament. It 

 bears cutting well, and is not liable to be disfigured by insects; 

 having fibrous roots, it robs the ground less than almost any other 

 shrub. It is one of the few plants that will grow in the smoke of 

 London ; it also thrives under the dripping of other trees. The wood 

 is hard and fit for timber. From the pulp of the berries a rose- 

 coloured pigment may be prepared ; with the addition of alum they 

 dye wool and silk of a good durable green. The following varieties 

 are those found chiefly in our gardens : 



L. v. leucocarpwm, the White-Berried Privet. 



L. v. xanthocarpum, the Yellow-Berried Privet. 

 L. v. chlorocarpvm, the Green-Berried Privet. 



L. v. lempervirent, the Italian or Evergreen Privet. 



L. v. variegatum, the Variegated-Leaved Privet. 



L. v. anguttifolium, the Narrow-Leaved Privet. 



L. Sinenee has lanceolate tomentose leaves, white flowers, and very 

 small brown berries. It is a native of China, near Canton. 



L. Japonimin is a native of Japan, with oblong ovate grooved 

 leaves, and white flowers growing to the height of 6 or 8 feet. 



