68 THE ORIGIN OF LIFE 



chief luminous phenomenon in the passage of the 

 discharge. 



Two difficulties, however, at once present them- 

 selves in connection with these long chains and 

 gigantic groups of molecules. In the first place, it is 

 not altogether obvious how they could, or should, 

 arise ; and in the second place, how, having so arisen, 

 they could manage to persist. 



There appears to be no evidence, from experiments 

 on viscosity, or otherwise, of the existence of these 

 large aggregates at ordinary pressures ; and, indeed, 

 the great frequency of collisions in such circumstances 

 would seem to be sufficient to hinder any possibility 

 of their formation. 



But it has been urged that, even at low pressures 

 and high vacua, the bombardment to which they 

 would be subjected should still be sufficient to 

 prevent them from having an opportunity of being 

 formed, or, if formed, of lasting for any appreciable 

 length of time. 



Such considerations, however, do not appear to 

 be well founded. The molecular aggregates may be 

 sufficiently stable, or, what amounts to the same 

 thing, the molecular forces brought into play may 

 be sufficiently large to hold the group together for 

 some time, against the bombardment to which it is 

 exposed ; whilst the persistence of the glow as in 

 phosphorescence, in some cases, shows, as will be 

 seen, that such unstable aggregates in gases at low 

 pressures are not only not impossible, but found 

 actually to occur, whilst the presence of the radiation 



