116 rnosr. [Leston xx. 



dows are firmly congealed. The limpid stream is 

 arrested in its career, and its formerly flowing sur- 

 face chained to the banks. The fluid paths become 

 a solid road ; and where the finny shoals were wont 

 to rove, the sportive youths slide, or with rapid 

 /motion skate along the crystal pavement. When 

 these and other wonders brought about by freez- 

 ing, are considered, surely it is not unnatural to 

 ask how are they occasioned ? This, perhaps, 

 cannot be answered with the wi?hed-for accuracy : 

 however, though the following observations do not 

 entirely determine the point under consideration, 

 they may yet be somewhat amusing. 



The fixing of a fluid body into a firm or solid 

 mass by the action of cold, is called freezing, or 

 congelation ; in which sense the terms are applied 

 to water when it freezes into Ice. By what mean 

 it is that fluid bodies should thus be rendered solid 

 by cold, the learned have not yet been able to dis- 

 cover. It would seem, however, that it arises from 

 the air then abounding with nitrous and saline par- 

 ticles, which insinuate themselves into the pores of 

 water, &c.by which mean they become hard. This 

 is the more probable when it is considered that 

 zmongfreezing mixtures, all kinds of salts, whether 

 alkaline or acid, are the principal ingredients. 



The process of congelation is always attended 

 with the emission of heat : it is also observed, that 

 water loses of its weight by freezing, being found 

 lighter after thawing again, than before it was 

 frozen. And indeed it evaporates almost as fast 

 when frozen, as when it is fluid : iiay, it has been 



observed, 



