A CHEMICAL PROLOGUE. 675 



disappeared as such, and that new substances with totally differ- 

 ent properties have taken their place. Yet this is all that a chemi- 

 cal reaction means. It may be studied any day in the kitchen. 

 The question of heat is quite as obvious. The coal has been 

 burned for that very purpose. At first sight these several facts 

 seem entirely unrelated. They have been selected quite at ran- 

 dom. A moment's consideration, however, will show that these 

 reactions, though seemingly dissimilar, are essentially identical. 

 Your cook may not be able to explain them to you, but she can 

 tell how they may be prevented, and that will serve the purpose 

 equally well. Her answer will be the same for all : Keep the air 

 from them. A fire with all the draught closed off goes out. Her- 

 metically sealed milk keeps fresh. Painted iron does not rust. 

 Bottled cider remains cider. Wood, not exposed to the air, will 

 endure for centuries. So, after all, the common element in these 

 reactions is not difficult to find. It is manifestly the air, for, in 

 the absence of that, they do not occur. To the chemist they are 

 all cases of oxidation. If he wishes to prevent them, he does just 

 what the cook does he keeps the oxygen of the air away from 

 them. That is all that Mr. Edison does when he pumps the air 

 out of the bulb of his incandescent electric light, so that the little 

 carbon horseshoe shall not burn up. 



Now, there is nothing occult about all this. The examples 

 given are not sufficient in number to warrant any very broad 

 generalization, but they can readily be extended, and conclusions 

 of universal application reached without other resource than that 

 found within one's self. Beginning in the home, one's conclusions 

 will be found to extend to the town, to the county, to the State, to 

 the world. One may finally think about the universe. The spirit 

 in which these investigations are conducted will be that of an 

 inquiring child. It is literally true in science that " a little child 

 shall lead them." The men who have built it up have labored 

 successfully in exact proportion as they have put their questions 

 directly to Nature rather than to books and to the sages. The 

 most hopeful sign that the growing scientific mind can disclose to 

 its fellows is that increasing simplicity of heart and mind which 

 has characterized all the immortals recognized by science. It is 

 this very faculty that has made men of science so notoriously 

 incompetent in business matters. We have come to expect little 

 news from a sharp bargainer. 



Questioning Nature in this childlike and natural fashion, life 

 becomes again a daily revelation, and inspiration a contemporary 

 event. It is paradise regained. There are still suffering and sor- 

 row, but there are also their antidotes, hope and faith. There is 

 universal law, but there is also universal love. The severe har- 

 monies of the universe lend grandeur and dignity to the pass- 



