308 Of the Propagation of Heat 



The discovery of this fact opens to our view one of 

 the most interesting scenes in the economy of Nature : 

 but in order to prepare our minds for the contemplation 

 of it, it will be not amiss to refresh our memory by re- 

 capitulating what has already been said on the Propaga- 

 tion of Heat in Fluids, and particularly in water; and 

 adding such occasional observations as may tend to elu- 

 cidate that abstruse subject. 



Those who enter into the spirit of these investigations 

 will not consider these repetitions and illustrations as 

 either superfluous or tiresome. 



CHAPTER III. 



Recapitulation^ and farther Investigation of the Subject. 

 All Bodies are condensed by Cold without Limitation^ WA- 

 TER ONLY EXCEPTED. Wonderful Effect s produced in 

 the World in consequence of the particular Law which ob- 

 tains in the Condensation of Water. This Exception to 

 one of the most general Laws of Nature ', a striking Proof 

 of Contrivance in the Arrangement of the Universe ; a 

 Proof which comes home to the Feelings of every ingenuous 

 and grateful Mind. This particular Law does not obtain 

 in the Condensation of SALT WATER. Final Cause of 

 the Saltness of the Sea. The Ocean probably designed by 

 the- Creator to serve as an Equalizer of Heat. Could not 

 have answered that Purpose had its Waters been fresh. 

 Final Cause of the Freshness of Lakes and inland Seas in 

 high Latitudes. Usefulness of these Speculations. 



A 



S the immediate cause of the motions in a liquid, 

 which take place on its undergoing a change of 



