WATER SOLVENT ACTION OF WATER, ETC. 



45 



exposure to the cold air above it, it will now remain at 

 the surface supported by the heavier, though warmer, 

 water beneath, and, finally, when the surface water lowers 



to zero, it will freeze. Ice, being a solid lighter than water, 

 will float upon it and being a poor conductor of heat will 

 prevent further radiation from the water and prevent its 

 freezing more than to a limited extent. Were it not for 

 this rather miraculous provision of nature, the lakes and 



