The Evolution of Chemistry. 143 



as it alone is able to stain diseased tissue in the eye and 

 leave the healthy tissue untouched. But why give more ? 

 Their name is almost legion, and more are coming. 



Within this same time new processes have been devised 

 for producing on a larger scale and at cheaper rates such 

 common substances as soda, chloroform, salicylic acid, oxy- 

 gen, nickel, aluminium, etc. The last-named metal is now 

 marketed at an exceedingly low price as compared with 

 that of a quarter of a century ago. The claim has lately 

 been put forward that a newer process has been devised by 

 which it can be produced as cheaply as iron. If this proves 

 true, then the present generation is about to see the most 

 wonderful industrial revolution that has occurred since man 

 came on this planet. Such a discovery would be apt to pro- 

 duce greater changes than did railways, telegraphs, and elec- 

 tric lights combined. It is probably too good news to be 

 true, and chemists generally are skeptical upon the matter. 

 Such a discovery would solve the problem of fire-proof, rust- 

 proof, and almost cyclone-proof homes. It would give us 

 finer, cheaper, and swifter railway-cars, steam and other 

 ships, and machinery. It would probably solve the problem 

 of aerial navigation. In fact, it would require pages to give 

 the changes it would introduce. But if we have not this, 

 we have one chemical discovery that is destined to do great 

 things for us in the not distant future as it becomes more 

 perfect in its development. 



It is said that Sir William Thomson was asked not long 

 ago to state what he believed to be the discovery of greatest 

 promise to the race that has been made within the present 

 generation. Pausing long enough to duly weigh the ques- 

 tion, he replied that in his judgment it was the storage 

 battery. Here we have bottled lightning that can run 

 trains and all forms of machinery without fire or smoke, 

 furnace or boiler, and not even a conducting wire to disfig- 

 ure the landscape or endanger life. It can be used for 

 heating or illuminating as well. Its invention let new light 

 into philosophical chemistrv and showed us that the attrac- 

 tions of our atoms are probably but a reversed condition of 

 what we call electrolysis. Here we have a discovery that 

 belongs equally to chemistry and physics, as it lies on the 

 boundary line of both. There is another of the same kind 

 that should be mentioned here. 



For a long time chemists have believed that the per- 

 manent gases might by a sufficient increase of pressure and 



