Fig. 6. COPPER calculated values of -^-. 



Observed values : x . 



264 MR. J. C. MAXWELL GARNETT 



Fig. 7. COPPER. 

 ( 1 ) K, observed for copper ruby glass Cu (X) : 



(1) Spheres (or molecules) in vacuo, v = 1 : 



(2) Spheres in glass, v = 1 5 : 



(3) Spheres in glass, v = 1 56 : 



Calculated values shown thus : Q. t v ~ 



(3) n -!L ! calculated for copper molecules in 



glass : 



Calculated values : O. 



(2) ~, calculated for copper spheres in glass, 



if 



- . 

 tf 







.( 



60 



E 



