EXPERIMENTS AND OBSERVATIONS 



COOLING OF LIQUIDS IN VESSELS OF PORCELAIN, 

 GILDED AND NOT GILDED. 



NOTHING affords more entertainment than to 

 compare the processes of the common arts of 

 life and the ordinary habits of the people in their 

 household operations with the principles of the physi- 

 cal and mathematical sciences. This comparison often 

 presents very curious points of resemblance, and leads 

 sometimes to very important improvements. 



In all countries where the daily use of tea has become 

 common among the rich, teapots of silver are preferred 

 to those of porcelain or earthenware, and the reason 

 given for this preference is that the beverage when pre- 

 pared in the former is of a better quality than when pre- 

 pared in the latter. I was, for a long time, of the 

 opinion that this idea was owing simply to prejudice, 

 and without foundation ; but, having discovered some 

 years since that metallic vessels, when clean and bright 

 on the outside, possess the property of causing warm 

 liquids which are put into them to retain their heat for 

 a very long time, I began to see that the preference in 

 question might be the legitimate result of long experi- 

 ence, as is almost always the case with those preferences 

 which in the end are universally adopted. 



VOL. II. l6 



