W. Thompson on the size of Atoms. 43 
f vortex atoms at present, I may at least say that soft 
arp, something of apparent cireumlocution must take the 
terms 
First, it is to be remarked that two molecules in collision 
Considering only the case i ae molecules, we might, then, 
e as half the average shortest 
distance reached in a vast number of collisions. The defini- 
tion I adopt for the present is not precisely this, but is chosen 
so ble the statement I have to 
