Page:Various Forces of Matter.djvu/79

Rh 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 show you to illustrate this power of cohesion of the particles of liquids. For instance, what would you propose to me if, having lost the stopper out of this alcohol bottle, I should want to close it speedily with something near at hand. Well, a bit of paper would not do, but a piece of linen cloth would, or some of this cotton wool which I have here. I will put a tuft of it into the neck of the alcohol bottle, and you see when I turn it upside down, that it is perfectly