212 LETTERS ON NATURAL MAGIC. 



LETTER 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 cir- 

 cumstances 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 Re- 

 markable one at the Solfaterra Echo at the Menai sus- 

 pension bridge Temporary deafness 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 mate- 

 rial world, there is scarcely one which, when well 

 considered, is not an object of wonder, yet those 

 which we have been accustomed to witness from 

 our infancy lose all their interest from the fre- 

 quency 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 almost discredits the evi- 

 dence 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 



