Excerpt from An Improved Apparatus and Method for the Analysis of Gas Mixtures by Combustion and Absorption
There are over 200 small orifices in such a plate, and the gas issuing is broken up into many fine bubbles, which apparently do not coalesce. A froth consisting of small bubbles separated by liquid films is formed at the surface of the reagent. This layer of froth is about 2 cm deep, and some absorption must take place here as well as in the actual passage through the pyrogallol solution. The froth very obligingly disappears when the gas flow through the perforated plate has ceased....