Pressure dependence of electroluminescence in dielectric liquids

The intensity of electroluminescence has been found to increase for benzene and to decrease for n-hexane, cyclohexane, chloroform, and n-hexane mixed with ethyl alcohol, with increasing hydrostatic pressure. No electroluminescence has been observed in carbon tetrachloride at fields up to the value close to breakdown strength. The results are briefly discussed in terms of electrohydro-dynamic motion and impact excitation of molecules.