66 THE YEAR. 



air, and water being the principal agents in the dis- 

 tribution ; and the former, unless when decomposed 

 by the action of an animal, a plant, or some other 

 substance, is an air or gas at all natural temperatures ; 

 while the latter exists solid in ice and snow, liquid in 

 water, and also in the state of invisible vapour, though 

 then it is only mechanically mixed with the atmo- 

 sphere, and held in suspension by the evaporative 

 power of that, a power which does not wholly depend 

 upon temperature, and the nature of which is not 

 perfectly understood. 



The way in which water is affected by heat, has some 

 important effects in the economy of the year, and tends 

 to render some changes gentle and gradual, which, but 

 for its peculiarities, would have been so instantaneous 

 as to prove destructive. The mean temperature of 

 running water in lakes and rivers, is considerably higher 

 than 39^, the temperature at which water is heaviest, 

 and that again is 7 above the freezing point. Both 

 those circumstances are of considerable importance in 

 the higher latitudes. 



If water did not become heavier when cooled to some 

 degree below the average temperature in these coun- 

 tries, the very first night of autumnal frost would cover 

 all the lakes and pools with ice ; and as the thawing of 

 ice consumes far more heat than the altering of the 

 temperature of liquid water, the transition from heat to 

 cold would be so rapid that the produce of the earth 

 would be destroyed. But in consequence of the pro- 

 perty under consideration, and of the ease with which 

 the atoms of wafer move through the mass, the water 

 acts as a regulator, until the fruits have been ripened, 



