174 ORIGIN AND NATURE OF LIFE 



ponent of the former, and Arrhenius as that 

 of the latter view. 



Kelvin, in his address to the British Associa- 

 tion at Edinburgh in 1871, put the proposition 

 thus : " When two great masses come into 

 collision in space, it is certain that a large 

 part of each is melted ; but it seems also 

 quite certain that in many cases a large 

 quantity of debris must be shot forth in all 

 directions, much of which may have experi- 

 enced no greater violence than individual 

 pieces of rock experience in a landslip or in 

 blasting by gunpowder. Hence and because 

 we all confidently believe that there are at 

 present, and have been from time immemorial, 

 many worlds of life beside our own, we must 

 regard it as probable in the highest degree 

 that there are countless seed-bearing meteoric 

 stones moving about in space. If at the 

 present instant no life existed upon this 

 earth, one such stone falling upon it might, 

 by what we blindly call natural causes, lead 

 to its becoming covered with vegetation." 



The view of Arrhenius is a more modern 

 variation ; he proceeds from the known facts 

 of bacteriology, that the minutest germs of 

 life float about in the air, many of them 

 ultra-microscopic in magnitude. These minu- 

 test germs of living matter may be carried 



