EXPLORING THE ATOM 



previously had contained only hydrogen, through 

 which an electric current had been discharged. 

 Professors ~Collie and Patterson told of the discovery, 

 of the gas neon under like circumstances. The repu- 

 tation of the investigators justifies the belief that all 

 sources of experimental errors were excluded, and 

 that a certain portion of the gases helium and neon 

 actually made its appearance in a bulb which at the 

 beginning of the; experiment had contained only, 

 hydrogen. 



This experiment seems by no means so startling 

 as it would have seemed a few years ago. The phe- 

 nomena of radioactivity have made us familiar with 

 the transmutation of one substance into another. In 

 particular it has been demonstrated, as we have seen, 

 that the alpha particles which fly off incessantly 

 from radium and various other radioactive sub- 

 stances are in reality molecules of helium, each con- 

 veying a double charge of positive electricity. So 

 the appearance of the element helium as the by- 

 product of another element is a phenomenon already 

 clearly established. 



But the peculiar significance of the new experi- 

 ments just reported is this: the new substances are 

 made to appear in the tube without the presence of 

 any radioactive substance, and at the will of the 

 operator, through the use of the electric current. 

 What is still more remarkable, however, is the fact 

 that helium and neon are both of higher atomic 

 weight than the hydrogen in the midst of which they 

 appear. Specifically the weight of hydrogen is 

 placed at unity, whereas helium is four times as 



123 



