3IO THE ORIGIN OF LIFE 



of mercury, and quite distinct from that whicli is 

 observed by the friction of mercury on glass. The 

 great luminous efficiency of the discharge in mer- 

 cury vapour may be attributed to the readiness 

 with which the mercury molecule or aggregate of 

 molecules breaks up. 



It is therefore worthy of note that so many of 

 the monatomic gases phosphoresce ; the ordinary 

 gases do not show this property except when, as 

 we have seen, condensation takes place on the 

 walls of the tube : in which case even the fluor- 

 escence of the metallic vapours is greatly increased. 



We attribute this to the influence of a substance 

 of high specific inductive capacity in enabling the 

 electrons to interchange, according to the theory 

 put forward. 



The monatomic gases, and other fluorescent gases, 



have a high specific inductive capacity, oxygen 



and air being exceptions. Thus the refractive 



indices of 



Cyanogen = 1-000834 



Nitrous oxide = 1-000503 



Phosphorous vapour = 1-001364 

 Arsenic = 1-001114 



The phosphorescence of oxygen does not need 

 a substance of high specific inductive capacity to 

 bring about the molecular aggregates. 



The motion of mercury on glass is well known 

 to give rise to luminosity. I have found it does 

 not take place in a Torricellian vacuum, but 

 depends upon the presence of air, and then spreads 



