The spectrum of sonoluminescence emitted by single bubbles of H-2, D-2
, He-3, and He-4 trapped in H2O and D2O has been measured. We find tha
t heavy water has a dramatic effect on the spectrum of hydrogenic gase
s, yielding a blackbody-type spectrum with a spectral peak at about 40
0 nm. The explanation of why such a small change in the driving fluid
leads to such a large spectral shift is unknown.