LIGNUM-VIT^ 



115 



gone one of tho changes leading towards the production of coal. If wood is 

 buried in moist earth there is tho production of carbonic acid from the elements of the 

 wood, and the wood is changed into either lignite or brown coal. Lignite and coal 

 differ chemically from each other. Lignite yields by dry distillation acetic acid and 

 acetate of ammonia, whereas coal produces only an ammoniacal liquor. (Kremeri.) 

 "Woody fibre gives rise to acetic acid ; therefore, lignite must still contain undecomposed 

 woody fibre. Tho following table gives the composition of several well-known 

 lignites : 



The products of the destructive distillation of lignite, by B. Niederstadt is well 

 deserving attention. The lignites examined came from the Khenish-Hessian basin. 

 1. Lignite from Meissner, of a red-brown colour and woody texture ; specific gravity 

 T12. 2. Lignite from Eheinhardswalde, grey or black, containing abundance of 

 resin; specific gravity 1'13. 3. Brilliant lignite of Meissner, black, fracture fibrous, 

 lustre vitreous ; specific gravity 1*32. 4. Lignite of Hirschberg, brownish-black, in 

 tree-like masses; specific gravity 1 '35. The following is their elementary composi- 

 tion : 



On distillation these lignites yielded solid, liquid, and gaseous products ; at a dark-red 

 heat, a brown tarry matter passing over along with combustible gases. To separate 

 the watery portion from the tar, common salt was added to the mixture, heated to 40. 

 The quantity of tar, when freed from water, amounted to 4 to 5 percent., and the watery 

 products 48 to 55 per cent., containing acetic acid and ammonia. The oily matters 

 distilled over at 95 to 220, leaving a black pitchy residue. The distillate, on agitation 

 with concentrated soda-lye, yields phenol. On fractional distillation, the portions 

 passing over up to 150 contain pyrrol and picoline, which boils at 135, and is distin- 

 guished from aniline by not giving a violet colouration with chloride of lime. The 

 part passing over about 220 solidified on cooling, yielding a crystalline mass soluble 

 in alcohol and ether. It melts at 49 to 51, and is a paraffin formed of hydrocarbons 

 OH 2n . It amounts to 1 per cent, of the lignite employed. The gaseous mixture, 

 from the Meissner lignite, consisted of: Hydrogen, 14-26; carbonic oxide, 40'12; 

 marsh-gas, 10'29 ; nitrogen, 4'09 ; carbonic acid, 2-10 ; ethylene and superior hydro- 

 carbons, 2-13. There appears, consequently, little prospect of using the gases from 

 lignite for lighting purposes. 



In Prussia, Austria, and many other parts of the Continent, lignite forms a very 

 important product, being largely employed for domestic and for manufacturing 

 purposes. In this country, with the single exception of the Bovey Heathfield formation, 

 which is used in tho adjoining pottery, lignite is not employed. See COAL. 



IilOrN"UlVT-VIT.2, or Guaiacum (Guaiacum officinale and G. sanctum"), a, very 

 hard and heavy wood. The fibrous structure of this wood is very remarkable ; the 

 fibres cross each other sometimes as obliquely as at an angle of 30 with the axis, 

 as if one group of the annual layers wound to the right, the next to the left, and 

 so on, with any exactitude. The wood can hardly bo split, it is therefore divided by 

 the saw. Lignum-vitse is much used in machinery for rollers, presses, mills, &c., and 

 for pestles and mortars, sheers for ship's blocks, skittle balls, and a great variety of 

 other works requiring hardness and strength. 



The gum guaiacum of the apothecary is extracted from this wood. 



12 



