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FARADAY 



in the form of water; and to show you how truly and 

 thoroughly these changes take place, I will take this tin 

 flask, which is now full of steam, and close the top. W 

 shall see what takes place when we cause this water of 

 steam to return back to the fluid state by pouring some cold 

 water on the outside. [The lecturer poured the cold water 



FIG. 66 



over the vessel, when it immediately collapsed.] You see 

 what has happened. If I had closed the stopper, and still 

 kept the heat applied to it, it would have burst the vessel; 

 yet, when the steam returns to the state of water, the vessel 

 collapses, there being a vacuum produced inside by the con- 

 densation of the steam. I show you these experiments for 

 the purpose of pointing out that in all these occurrences 

 there is nothing that changes the water into any other 

 thing; it still remains water; and so the vessel is obliged 

 to give way, and is crushed inward, as in the other case, by 

 the farther application of heat, it would have been blown 

 outward. 



And what do you think the bulk of that water is when it 

 assumes the vaporous condition ? You see that cube [point- 



