Abstract The low frequency (<10 cycles per second) content of body waves from chemical explosions has been studied. The traces recorded on an FM magnetic tape recording system have been reduced for instrumental effects. The corrected data have a coherent but peculiar distribution. The shape of the distribution suggests an hypothesis about the nature and behavior of the medium. Not all facts are consistent with the proposed hypothesis. This may be due to low level of the energy spectrum considered and the nature of the FM recording system used. Digital recording, permitting greater accuracy, is suggested.