38 THE IRON ORE DISTRICT OF EAST TEXAS. 



CHAPTER II. 



LIGNITES AND THEIR UTILIZATION, WITH SPECIAL 

 REFERENCE TO THE TEXAS BROWN COALS. 



DR. OTTO LERCH. 



Brown coal,* often called lignite, is but a variety of mineral coal. It does 

 not differ in its chemical composition from other mineral coals. Graphite, 

 anthracite, and the large number of the different varieties of stone coal all 

 possess the same constituent chemical elements — carbon, hydrogen, nitrogen, 

 oxygen, and a number of inorganic compounds called ash. The varying pro- 

 portion of the constituent elements alters the physical and chemical properties 

 of the coals, and, correspondingly, their economic value. The cause of this 

 different proportion of the constituent elements in the materials is generally, 

 though not always, the geological age of the coals — the amount of carbon 

 contained in them increasing with increasing age. Lignite is a product of 

 Mesozoic and Tertiary times, and its more recent origin is indicated by its 

 woody structure being generally well preserved. The formation of the brown 

 coal has taken place through long geological ages, under varying conditions, 

 and consequently the composition, quality, and economic value of the lignites 

 change from a hard black and glossy coal, of which the ligmtic nature can 

 be detected only by chemical analysis, through various stages to a product 

 resembling the common peat but recently formed in our marshes. 



Brown coal is well distributed all over the globe, and many of its deposits 

 are mined and utilized in various parts of the civilized world. Germany 

 produced in 1887, 18,000,000 tons of lignite, constituting one-fourth of her 

 total coal production, and all other European countries produced the brown 

 coal in similar proportions. 



The rapid growth of manufacture, and with it the increasing demand for 

 fuel, has steadily increased the production of brown coal, and countless experi- 

 ments have been conducted to enhance the intrinsic value of this coal by 

 making it suitable for various manufacturing purposes. 



The patient and constant labor of scientist and manufacturer, liberally 

 supported by capital, has been successful, and brown coal is now used, accord- 

 ing to its quality, in the manufacture of paraffine and mineral oils, illuminat- 

 ing gas, blacking, powder, tanning material, artificial manure, tar, coke, 

 briquettes, and for smelting purposes. In addition to this, the lignite is 

 largely in use in a raw state or in form of briquettes as fuel for household 

 purposes. 



* In this article lignite and brown coal are used as synonomous terms. 



