The density of thin vapor-deposited films of cadmium sulfide was determined
by spectrophotometry combined with Rutherford backscattering spectrometry.
The density determined was 0.95 +/- 7% of the hulk value for the CdS. The
Lorentz-Lorenz law, based upon the measured data on the index of refraction
of the films, suggests a value of the density of the films close to the on
e obtained in the present work.