Rotational Energy Distribution of OH Molecules from theλ3064Band

The rotational energy distribution of the OH molecules has been studied by photometric measurement of the $\lambda 3064$ band. The band excited in the oxy-hydrogen flame and in the copper arc shows a thermal distribution of intensities from which temperatures of 3275°K and 6350°K, respectively, are calculated. The spectrum excited in vacuum tube discharges shows abnormal rotational energy which varies with the pressure of the water vapor in the tube. At current densities used in the experiment, no reduction of rotational energy could be obtained by addition of excess foreign gas.