The damping of sound by frothy liquids

Abstract

The fact that a tumbler containing a frothy liquid gives a dull sound when struck is familiar to every one, but I cannot find that any explanation of the rapid damping of the vibrations, which is indicated by the character of the sound, has been published. The converse case, namely, that of waves propagated through a gas in which small solid or liquid spheres are disseminated, has received considerable attention, and the results deduced, which agree with observation, are to the effect that although the presence of small obstacles does cause some damping, it is very small in amount.