of Fig. 2, C, till a little secondary ring is formed, which sometimes remains attached, is at other times separated and divided into several others, that will, if they are small enough, continue for a long time suspended in the liquid.
All of these little rings, with the curved filaments supporting them, form in the water a very marked figure—a kind of diadem, a fantastic hydra, or a diaphanous cup (Fig. 2, B)—the singular figure of which causes us to neglect at first certain less visible details in which the real mechanism of the phenomenon is revealed; and a very light or a very dark ground, according to the character of the colored liquid, is required in order to discover the frame-work and the processes of the formation.
Rings of vapor are capable of attaining considerable dimensions without breaking. If we take a box, make a hole in it, substitute a stretched cloth or plate of metal for one of its sides, and develop in it vapors of phosphoric acid or muriate of ammonia, we can easily by
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/PSM_V20_D194_Same_experiment_performed_with_a_box.jpg/300px-PSM_V20_D194_Same_experiment_performed_with_a_box.jpg)
Fig. 5.—The same experiment, performed with a box made of playing-cards. The box is filled from the mouth at the hole in the upper side.
means of a slight blow cause wreaths several inches in diameter, exhibiting the structural details of the liquid rings, to shoot out to a considerable distance. A soap-bubble filled with smoke produces similar effects when it bursts; and a cubic box made of playing-cards