116 SOUND. 



appear like a cloud; and the same effect applies precisely to 

 sound. Therefore, if the two media are of different charac- 

 ters, the one a gas, the other a fluid, as in the case of falling 

 rain; or the one a gas, and the other a solid, as in the case of 

 falling or new-fallen snow; the scattering and deadening of 

 the sound will be still more complete. 



ESTHER. 



I can tell you of an experiment which will show you this 

 very clearly. 



FREDERICK. 



What is it 1 ? 



ESTHER. 



If a tall glass be half filled with sparkling champagne, or 

 any other fermented liquid, the glass cannot be made to ring, 

 by a stroke upon its edge, so long as the effervescence con- 

 tinues, and while the wine is filled with air bubbles; but, as 

 the effervescence subsides, the sound gradually becomes 

 clearer and clearer, until, at last, when the air bubbles have 

 disappeared, the glass rings as usual. 



HENRIETTA. 



Let us try this at dinner to-day. 



MRS. F. 



Humboldt has employed this interesting experiment to ex- 

 plain the well-known phenomenon of distant sounds being 

 heard more distinctly at night than at day. 



ESTHER. 



In what manner"? 



MRS. F. 



In a hot day, when warm currents ascend from the heated 

 ground, and mix with the cold air above, of a different den- 

 sity, the atmosphere is a mixed medium, as in the case of the 

 glass of champagne. 



