Page:Various Forces of Matter.djvu/78

66 of fluid mercury, the particles of which have attraction sufficient to make them hold together all the way through the air down to the glass itself: and if I pour water quietly from a jug, I can cause it to run in a continuous stream in the same manner. Again, let me put a little water on this piece of plate glass, and then take another plate of glass and put it on the water; there! the upper plate is quite free to move, gliding about on the lower one from side to side; and yet, if I take hold of the upper plate and lift it up straight, the cohesion is so great that the lower one is held up by it. See how it runs about as I move the upper one, and this is all owing to the strong attraction of the particles of the water. Let me show you another experiment. If I take a little soap and water—not that the soap makes the particles of the water more adhesive one for the other, 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