M. C. Lea on certain phenomena of Light. 373 
spheres have a greater or less index of refraction than the 
medium, for the reason already given. 
Another portion of the ray R’ passes through the sphere at 
N and interferes with a ray twice reflected, viz: at N and M, 
with production of red diffused light in some direction at N P’. 
The phenomena which I have endeavored to describe and 
not the case. 
I have included in this brief description a few only of a very 
large series of experiments. The conditions may be greatl 
transparent to light (and also to heat, as shown by Melloni). 
interferences, but in this case the interference is between two 
nt is not new 
