126 CORRELATION OF PHYSICAL FORCES. 



mind at least, far more unphilosophical than to suppose a 

 boundless universe of matter existing in forms and actions more 

 or less analogous to those which, as far as our examination 

 goes, pervades space. But without speculating on topics in 

 which the mind loses itself, it may not unreasonably be 

 expected that a greater amount of light would reach us from 

 the surrounding self-luminous spheres, were not some portion 

 lost as light by its action on the medium which conveys the 

 impulses. What force this becomes, or what it effects, it 

 would be vain to speculate upon. 



After advancing the above conjecture, I found that Struve 

 had been led, from astronomical observations, to the conclu- 

 sion that some light is lost in the interplanetary spaces ; he 

 gives as an approximation one per cent, as lost by the passage 

 of light from a star of the first magnitude, assuming a mean 

 or average distance. 



