58 Chemistry. [Lecture 26. 



so as to reach both rings, and be suspended in 

 them while it remains warm. 



If spirit of wine is contained in an oblong 

 vessel, and immersed in hot water, the spirit will 

 be observed to rise like the mercury in a ther- 

 mometer. 



A bladder, with a little air in it, when heated 

 will expand so as almost to burst ; but on remov- 

 ing it into the cold, it condenses and shrinks to 

 its former state. 



Rarer and lighter bodies expand more than the 

 heavier and denser; but this proportion does not 

 always exactly correspond to the respective den- 

 sity and rarity of matters; for metals expand 

 more than glass. 



As an exception to this doctrine it has been 

 observed, that water suddenly swells in passing 

 from a fluid to a solid state : but this is to be ex- 

 plained upon different principles. Boyle took a 

 brass tube, three inches in diameter, and put 

 some water into it; he then brought down into 

 the tube a plug with a weight placed at the head 

 of it of 7ilb., exposing the tube to the cold, and 

 the water freezing and expanding itself raised 

 the 74lb. The Florentine academicians filled a 

 brass globe with water, closing the orifice by a 

 well-fitted screw, and immersed it in freezing 

 water; but as the sides were too thick, it did not 

 burst. They then pared off such a quantity of 

 the brass as left the sides of the globe unable to 

 resist the expansion of water; the force which 



