130 MODERN SCIENCE READER 



builder, and the mechanical engineer, while the manufac- 

 turing chemist derives benefit from the demand for nitric, 

 sulphuric, and hydrochloric acids, soda, dextrine, and other 

 substances consumed in vast quantities in the manufac- 

 ture and application of dyes. 



In Germany the development of the coal-tar dye in- 

 dustry has brought another and more general benefit, for 

 it was the principal cause of the establishment of the 

 imperial patent office, in 1877. 



Allied to the production of dyes is that of remedies, 

 germicides, explosives, perfumes, photographic developers, 

 and many other valuable substances from coal tar. This 

 industry has attained gigantic proportions. A few of its 

 most valuable and extensively used products are carbolic 

 and salicylic acids, saccharin, antipyrine, and other febri- 

 fuges, artificial vanilla and artificial musk. 



The coal-tar dye industry has conferred a benefit of 

 incalculable value upon bacteriology and upon all man- 

 kind by furnishing dyes which, when applied to micro- 

 scopic preparations, make it possible to distinguish and 

 recognize the germs of typhoid, cholera, tuberculosis, and 

 other diseases. 



The first aniline dye was produced in England, but the 

 manufacture of the coal-tar colors has been developed 

 chiefly in Germany, where it may be regarded as a national 

 industry. 



