311 



Hence it appears that the condensation of water, or 

 increase of its specific gravity in being cooled ii\ de- 

 grees of Fahrenheit's scale, is at least ninety times greater 

 when the water is boiling-hot, than when it is at the mean 

 temperature of the atmosphere in England (542-"}, or 

 within 12\ degrees of freezing, (for 18 is to 0.2 as 90 

 to I.) 



All liquids, it is true, in cooling, are more condensed 

 by any given change of temperature when they are very 

 hot than when they are colder ; but these differences are 

 nothing compared to those we observe in water. 



The ratio of the condensation in cooling from 212° to 

 189!-° to that in cooling from 54^° to 32° in each of the 

 under-mentioned fluids has been shown, by the experi- 

 ments of M. de Luc, to be as follows : — 



Olive-oil ..... 



Strong spirits of wine 



A saturated solution of sea-salt in water 



Pure water ..... 



as iJq^o to I 



as i^J>o to I 



as \^^-^ to I 



as 90 to I 



The difference between the laws of the condensation 

 of pure water and of the same fluid when it holds in 

 solution a portion of salt is striking ; but when we 

 trace the effects which are produced in the world by that 

 arrangement, we shall be lost in wonder and admiration. 



