298 J. Lovering—Mathematical and Philosophical 
difficulties and objections. Still, it is consistent not only with 
Arago’s negative result, but with the experiments on diffraction 
Next we ask, if it is certain that even the motion of the lumi- 
: € origin; or is the conservation of these elements a0 
essential attribute of the luminiferous medium. It has been said 
Evidently, there is an obscurity in the minds of i 
and an uncertainty in all, when they reason upon the mechanical 
_ Constitution of the ether, and the fundamental ae of light. The 
