Page:On the various forces of nature and their relations to each other.djvu/85

Rh but it certainly has the power of continuing in a better manner the attraction of the particles (and let me advise you, when about to experiment with soap-bubbles, to take care to have, everything clean and soapy). I will now blow a bubble; and that I may be able to talk and blow a bubble too, I will take a plate with a little of the soapsuds in it, and will just soap the edges of the pipe, and blow a bubble on to the plate. Now, there is our bubble. Why does it hold together in this manner? Why, because the water of which it is composed has an attraction of particle for particle,—so great, indeed, that it gives to this bubble the very power of an india-rubber ball; for you see, if I introduce one end of this glass tube into the bubble, that it has the power of contracting so powerfully as to force enough air through the tube to blow out a light (fig. 22)—the light is blown out. And look! see how the bubble is disappearing, see how it is getting smaller and smaller.

There are twenty other experiments I might shew you to illustrate this power of cohesion of the particles of liquids. For instance, what