This communication was intended to illustrate by experiments with the solution of glycerine and oleate of soda, devised by Plateau, the mode in which a soap-bubble is detached as a closed shell from the mouth of a funnel; the mode in which two bubbles unite; and the process of cutting one into two or more.

A statical investigation of the form of an unclosed film, blown with coal gas, was given (the kinetic problem presenting very grave difficulties), and the results were shown to be in accordance with observation, so far as the eye can follow the rapid change which takes place in the neck of the film just before the closed bubble is detached.