MATTER AND ENERGY. 49 



LUMINOUS ETHER. 



Light in its passage from the sun seems to be 

 wafted on waves of a tenuous medium which has been 

 denominated ether on account of its thinness or mar- 

 velous tenuity. Although ether is an essential sub- 

 stance, it is too subtle to be weighed or measured ; in 

 fact such a material as luminous ether has been 

 doubted has been denied an existence. But the 

 presence of such a body has been demanded to account 

 for certain phenomena in connection with the transmis- 

 sion of solar or luminiferous rays. It has been con- 

 tended that all stellar interspaces and the interstices of 

 molecules are occupied by a universal and circumam- 

 bient ether. How, it is asked, could the light of fixed 

 stars be conducted to the earth except through such 

 a medium. The nebular theory furnishes tenuous 

 media which have the qualities for transmitting light 

 and possibly sound. All nebulous bodies reduced to 

 extreme tenuity are easily made undulatory. When 

 two meteors collide in space, the concussion is posi- 

 tively imparted to the nebulous environment, and 

 conducted indefinitely through waves of ten nous matter. 

 The impulse of sound would be transmitted as well as 

 light and heat, and perhaps electricity. The photo- 

 sphere about the sun is a luminous ether, but need not 

 necessarily be distinct from tenuous matter in general. 

 When it is considered that an atom of hydrogen is the 

 basis of all matter, and that all molecules and masses 

 are but multiple combinations of the subtle stuff, we 

 may not be astonished to hear that luminous ether is 

 a composition of hydrogen and helium, and that 

 helium was only another form of hydrogen ! Al- 

 though the oxy hydrogen flame is very hot, it sends 



