A comparison is made in this study between the δ-ray densities expected theoretically and those observed experimentally on charged particle tracks in Ilford G5 emulsions. The energies of δ-rays are determined here by means of grain-counting measurements and energy-loss considerations. Using this method of energy determination and the theoretical formula for δ-ray density, good agreement has been found with the experimental distributions on proton, μ-meson, deuteron, and α-particle tracks. The agreement is satisfactory both in absolute value and in the shape of the δ-ray density distribution. These results are considered to show that the δ-ray technique is suitable as an absolute method of charged particle identification in photographic emulsions.