The intensity of bioluminescence from firefly lantern extracts elicited by the addition of ATP has been reported to be proportional to the amount of added ATP. The intensity of bioluminescence elicited by the addition of 2.0 X 107 mole ATP to a solubilized fraction of firefly lantern homogenate was decreased by administration of diethyl ether or halothane. Relative intensity of bioluminescence decreased linearly when plotted against the logarithmic scale of the concentrations of the anestheties. With 6 per cent diethyl ether the dose-response curve for ATP concentration and light intensity was shifted to the right parallel to the control.
The inhibition of bioluminescence by anesthetics was reversed to control value by elimination of the anesthelic from the medium.