GRAVITATION OF CARBONIC ACID. 



17 



I want you to see is that this steam gravitates. 

 I have here (Jig. 2) a large vessel placed upon 



Fig. 2. 



a balance, and the moment I pour this steam 

 into it you see that the steam gravitates. Just 

 watch the index, and see whether it tilts over or 

 not. [The Lecturer here poured the carbonic 

 acid out of the glass in which it was being 

 generated into the vessel suspended on the 

 balance, when the gravitation of the carbonic 

 acid was at once apparent.] Look how it is 

 going down. How pretty that is ! I poured no- 

 thing in but the invisible steam, or vapour, or 

 gas which came from the marble, but you see 

 that part of the marble, although it has taken 

 the shape of air, still gravitates as it did before. 

 c 



