The Wonders of Coal Tar 



No branch of industrial chemistry yields more widely appli- 

 cable and varying products than the distillation of coal 



By George M. Oaks 



IF you have ever tried to run a furnace 

 you know that coal gives off gas when 

 heated. Yes, and you probably know 

 that most of our illuminating gas comes 

 from coal in that way. In by-product coke 

 ovens the coal is heated in closed vessels so 

 that the coal is distilled and not burnt up. 

 But did you realize that this is the basic 

 operation leading to hundreds of common, 

 everyday products: tar, coke, lampblack, 

 creosote, carbolic acid, naphtha, sal-am- 

 moniac, ammonia, varnish, photographic 

 materials, explosives, drugs, mineral van- 

 illa, dyes and many others? 



Coal, when heated, is chemically dis- 



membered to form several new substances 

 which can be recombined or united with 

 other substances to form new products. 

 A toy house, made out of a child's building 

 blocks, can be taken apart and a new house 

 built, either out of the same blocks or by 

 adding others. This process, it should be 

 borne in mind, is a mechanical one, and 

 only serves to illustrate in a simple way the 

 distillation of coal, which is a chemical 

 process. 



Synthesis, or the process of building up 

 new products from simpler ones, is best 

 illustrated in making dyes. There are now 

 so many shades of the same color that we 



Coal is a precious mineral. Its value can be better appreciated by noting some of the products 

 such as dyes, explosives, drugs and perfumes, obtained directly or indirectly from its distillation 



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