272 LETTERS ON NATURAL MAGIC. 



LETTEE IX. 



Singular effects in nature depending on sound Permanent character 

 of speech Influence of great elevations on the character of sounds, 

 and on the powers of speech Power of sound in throwing down 

 buildings Dog killed by sound Sounds greatly changed under 

 particular circumstances Great audibility of sounds during the 

 night explained Sounds deadened in media of different densities 

 Illustrated in the case of a glass of champagne, and in that of 

 new-fallen snow Remarkable echoes Reverberations of thunder 

 Subterranean noises Remarkable one at the Solfaterra Echo 

 at tlie Menai Suspension Bridge Temporary deaf ness produced in 

 diving-bells Inaudibility of particular sounds to particular ears 

 Vocal powers of the statue of Memnon Sounds in granite rocks 

 Musical mountain of El-Nakous. 



ALTHOUGH among the phenomena of the material world 

 there is scarcely one which, when well considered, is not 

 au object of wonder, yet those which we have been 

 accustomed to witness from our infancy lose all their 

 interest from the frequency of their occurrence, while to 

 the natives of other countries they are unceasing objects of 

 astonishment and delight. The inhabitant of a tropical 

 climate is confounded at the sight of falling snow, and he 

 almosts discredits the evidence of his senses when he sees 

 a frozen river carrying loaded waggons on its surface. 

 The diffusion of knowledge by books, as well as by 

 frequent communication between the natives of different 

 quarters of the globe, have deprived this class of local 

 wonders of their influence, and the Indian and the 

 Scandinavian can visit each other's lands without any 

 violent excitement of surprise. Still, however, there are 



