3o8 • 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 Effects 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 ftot 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 



