in Fhtids. 325 



temperature of 32° before ice could have been formed, 

 this event could not have happened till the water had 

 given off as much Heat as would be sufficient to melt 

 a covering of ice above 57 feet thick ! 



This quantity of Heat would be sufficient to heat, to 

 the point of boiling, a quantity of ice-cold water as large 

 as the lake, and 49 feet deep. 



We cannot sufficiently admire the simplicity of the 

 contrivance by which all this Heat is saved. It well 

 deserves to be compared with that by which the seasons 

 are produced; and I must think that every candid en- 

 quirer who will begin by divesting himself of all un- 

 reasonable prejudices will agree with me in attributing 

 them both to the same author. 



When we trace still farther the astonishing effects 

 which are produced in the world by the operations of that 

 simple law Vv'hich has been found to obtain in the con- 

 densation of water on its being deprived of Heat, we 

 shall find more and more reason to admire the wisdom 

 of the contrivance. 



That high latitudes might be habitable, it was neces- 

 sary that vegetables should be protected from the effects 

 of the chilling frosts of a long and severe winter ; but if 

 it be true that watery liquids do not part with their Heat 

 but in consequence of their internal motions, and if 

 these motions are occasioned merely by the change pro- 

 duced in the specific gravity of those particles of the 

 liquid which receive Heat, or which part with it, who 

 does not see how very powerfully the sudden diminution 

 and final cessation of the condensation of water in cool- 

 ing, as soon as its temperature approaches to the freezing 

 point, operates to prevent the sap in vegetables from 

 being frozen ? 



