68 POPULAR SCIENCE MONTHLY. 



the food of all civilized nations is better and more abundant than 

 it was before the chemist gave his aid to its production. Adul- 

 teration, always practiced, is now easily detected by chemical analy- 

 sis, and, though the evil still exists, the remedy for it is in sight. 

 To Liebig, who gave to agricultural chemistry its first great impulse 

 forward, mankind is indebted to an amount which is beyond all 

 computation. 



In manufactures the influence of chemistry is seen at every 

 turn. When the century began, probably no industrial establish- 

 ment in the world dreamed of maintaining a chemical laboratory; 

 to-day, hundreds are well equipped and often heavily manned for 

 the sole benefit of the intelligent manufacturer. Coal gas is a 

 chemical product; its by-products are ammonia and coal tar; from 

 the latter, as we have seen, hundreds of useful substances, the dis- 

 coveries of the last half century, are prepared. Better and cheaper 

 soap and glass owe their existence to chemical improvement in the 

 making of alkalies; chemical bleaching has replaced the tedious 

 action of sunlight and dew; chemical dyestuffs give our modern 

 fabrics nearly all their hues. Metallurgy is almost wholly a group 

 of chemical processes; every metal is extracted from its ores by 

 methods which rest on chemical foundations; analyses of fuel, flux, 

 and product go on side by side with the smelting. The cyanide and 

 chlorination processes for gold, the Bessemer process for steel, are 

 apt illustrations of the advances in chemical metallurgy; but be- 

 fore these come into play the dynamite of the miner, another chem- 

 ical invention, must have done its work underground. For rare 

 minerals, the mere curiosities of twenty years ago, uses have been 

 found; from monazite we obtain the oxides which form the mantle 

 of the Welsbach burner; from beauxite, aluminum is made. The 

 former waste products of many an industry have also revealed 

 unsuspected values, and chemistry has the sole honor of their 

 discovery. 



In education, chemistry has steadily grown in importance, until 

 a single university may have need of as many as twenty chemists 

 in its teaching staff, teaching not only what is already known, but 

 also the art of research. As a disciplinary study, chemistry ranks 

 high in the college curriculum, and it opens the way to a new 

 learned profession, equal in rank with those of more ancient 

 standing. 



For the material advancement of mankind the nineteenth cen- 

 tury has done more than all the preceding ages combined, and sci- 

 ence has been the chief instrument of progress. Scientific meth- 

 ods, experimental investigation, have replaced the old empiricism, 

 and no man can imagine where the forward movement is to end. 



