Electro-Optical Kerr Effect in Gases

The Kerr constant $B$ of C${\mathrm{O}}_2$ has been measured as a function of density from 0.06 to 0.32 g/${\mathrm{cm}}^3$ and as a function of temperature from 7.2 to 34.6°C. The results are in agreement with the Langevin-Born theory. The absolute value of $B$ for C${\mathrm{O}}_2$ has been measured and is 0.34×${10}^{-10\mathrm{}}$ per atmosphere for wave-length 4550A and temperature 34.6°C. This is also the theoretical value of $B$ for C${\mathrm{O}}_2$. The probable error of the measured value is 2 percent. The absolute value of $B$ for ${\mathrm{N}}_2$ measured by comparison with C${\mathrm{O}}_2$ is 0.057×${10}^{-10\mathrm{}}$ for the above wave-length and temperature, with a probable error of 3 percent. The corresponding theoretical value for ${\mathrm{N}}_2$ is 0.050×${10}^{-10\mathrm{}}$. The Kerr constant of ${\mathrm{H}}_2$ is shown to be less than 0.01×${10}^{-10\mathrm{}}$ which is not in disagreement with the theoretical value of 0.005×${10}^{-10\mathrm{}}$.