274 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1933 



building locked. He pushes; he knocks; he gets help; he rigs up a 

 machine to batter down the door; he makes a small hole through 

 which he sees signs of activity within the building; he builds a 

 bigger and better battering ram; he finally breaks down the door 

 and goes in. Within the building he finds a huge factory; giant 

 cranes carry around great masses of material; enormous machines 

 pre^s, hammer, and draw this material into various shapes. Stu- 

 pendous forces are at work. The building shakes, and from time 

 to time a little pebble on the fire escape is shaken down from one 

 step to another. 



So, I suspect, may sometime be resolved the peculiarities and puz- 

 zles of our present quantum theory — by small external manifesta- 

 tions of the enormous energy which we know to exist within the 

 nucleus, but about which we now know too little even to make a 

 guess as to how it may influence our present theories. 



Be this as it may, where have we left the alchemist? We left him 

 dead, killed by the chemist who had destroyed his hopes of effecting 

 the transmutation of elements. But now the physicist has brought 

 him to life again, with renewed vigor and enthusiasm. For if the 

 atomic nucleus is a structure of electrons and protons, it should be 

 possible to break up this structure or to add to it, and thus to change 

 one chemical element into another. The agencies are no longer earth, 

 water, air, and fire, but electricity and probably electrical particles 

 shot with tremendous speeds into nuclei. The goal is not gold and 

 silver but energy. And with the alchemist, who is a practical man 

 trying to get something, is working the physicist, who is not an 

 impractical man, trjnng to learn something. In fact, they are one 

 and the same man. 



A most significant event in this story was the discovery of radio- 

 activity by Becquerel 36 years ago. Its significance became evident 

 when Rutherford showed that the alpha and beta particles are, re- 

 spectively, helium nuclei and electrons which are shot out of the 

 nuclei of radioactive atoms with tremendous speeds, approaching 

 that of light. Its significance became greater when Rutherford 

 further showed that the parent atoms, in thus ejecting these particles, 

 transform into atoms of different chemical elements. The law of 

 this transmutation was thus stated by Fajans: Expulsion of a beta 

 particle changes the atom into the next higher one in the periodic 

 table, and the expulsion of an alpha particle changes the atom into 

 one which is two steps lower in the table. Here, for the first time, 

 were authenticated cases of transmutation of elements. 



The energies liberated in radioactive transformation are prodi- 

 gious, in comparison with the amount of material involved. For 

 example, radium continually gives off about enough energy to raise 



