Abstract
Large amplitude, occasionally periodic, oscillations occur in the intensity of light emitted from a number of solutions subject to illumination at constant intensity.Several examples of this phenomenon, including a new one, biacetyl-oxygenin acetonitrile have been investigated. It is concluded that the observed oscillations are spatial as well as temporalin character and that they are driven not by the photochemistry of the systems but by time-dependent convective motions within the fluid.