CHEMICAL AFFINITY 61 



I were to put it into boiling water it would not go through at 

 all. Again, as soon as the heat escapes from bodies, they 



FIG. 32 



collapse: see how the air is contracting in the vessel now 

 that Mr. Anderson has taken away his lamp; the stem of it 

 is filling with water. Notice too, now, that although I can 

 not get the tube through this hole or into the gauge, the 

 moment I cool it, by dipping it into water, it goes through 

 with perfect facility, so that we have a perfect proof of 

 this power of heat to contract and expand bodies. 



