Popular 'Science Mdnthlf)^ 



87^ 



in sufficient quantity to meet our demand 

 entirely, though it will be if the present 

 increase in production continues. 



Aniline Dyes Valuable in Bacteriology 



Aside from the common uses of aniline 

 dyes may be noted the vast requirements 

 of bacteriology. This science has made 

 incredible progress since the staining of 

 microscopic preparations with aniline dyes 

 has enabled scientists to distinguish and 

 recognize germs. Thus typhoid, cholera, 

 tuberculosis, and other baffling diseases 

 have been defined and studied. 



The most familiar explosive 

 in the minds of mortals 

 today is T. X. T. 

 (tri - nitro - toluene) 

 — a coal tar prod- 

 uct. It is an oil 

 belonging to the 

 benzol group, and 

 obtained by the 

 distillation of pri- 

 man,^ oil. It is 

 the result of com- 

 bining nitric acid with ^ 

 pure toluene. When being ^ 

 poured into shells, T. N. T. looks 

 like thick, syrupy chocolate. 



Carbolic Acid Has Many Uses 



Phenol (carbolic acid) is consumed in 

 the United States at the annual rate of 

 from eight to ten million pounds. The pro- 

 duction of certain explosives depends on 

 phenol. It is used in making picric acid 



( Taniun dye) ( Tajinj^ and Acid Dye) 

 RED 1 (RED 

 t/tovrt Taamn Dye) ( Taimin Dye) 

 RED 



Whole trainloads of 

 wood to be cre- 

 osoted are run into 

 long cylinders and 

 allowe[d t,o s.'oak 

 for several days 



A square yard of 

 wood block pave- 

 ment contains 45.36 

 pints of creosote oil 



and also aniline colors. 



The great value of phenol 



was still further heightened 



by the invention, b\' Dr. L. H. 



Baekeland, of a peculiar resinous 



substance which can be used in place 



of hard rubber. It seems like a magician's 



trick to combine two such strong-smelling 



liquids as carbolic acid and formalin to 



HitroBeniol 



^^^^M I^^Kl^l \^-n^ry^ |Pht.3Acid| fe*ffi!5l lA»tl«c,nan 



Benzol 



Toluol 



^ 



Xykd 



Nitro 

 Waphlhalin 



Naphthalin 



Unidifapfathi 



Anthracim 



UGHTOIL 



JMEMOMOCJ 



HEAVY OIL I 



This chart will give some idea of the formation of various red dyes. It may be noted that 

 niost ot these colors start from light oil; also that certain shades may be formed in two ways 



