COHESION OF THE PAETICLES OF LIQUIDS. 67 



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 



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