INFRA- ASTRONOMY 49 



being recaptured. The infra-man therefore has the 

 gorgeous spectacle of two suns majestically revolving 

 round each other, each attended with its planets, one 

 of them being transferred from one system to another 

 as a pledge of union. 



The above process is what happens in the forma- 

 tion of, say, a hydrogen molecule. The molecule is 

 really a binary star consisting of two atoms linked 

 by electrostatic force. If the speed of encounter is 

 excessive the result is two free-flying atoms, one 

 with a positive and the other with a negative ele- 

 mentary charge. Needless to say, when two such 

 atoms meet again their union is considerably faci- 

 litated by their electrostatic attraction. 



When from any cause the molecule is split up, 

 each atom will take its own electrons away with it, 

 and the atoms will constitute what is called " nascent 

 hydrogen." It is easily seen that the latter must 

 possess more pronounced combining properties than 

 neutral hydrogen. The splitting-up of molecules 

 into charged atomic systems is called ionisation. 

 Such ionisation may be brought about not only by 

 collision, but by a number of other agencies, such 

 as Rontgen rays, or ultra-violet light. There are 

 probably also cases of what may be called spontaneous 

 ionisation, brought about as follows: 



The superior or outer electrons of each system 

 revolve inM. r the attraction of the central positive 

 body. They undergo perturbations by the other 



