MENTAL DIFFERENCE AND DISORDER. 227 



similar terror general disturbance in flocks of sheep 

 (Figuier). 



All noises that are discordant, loud, multiform, especially 

 if they are in addition sudden, or sounds that are simply 

 sudden, startling, loud, unaccustomed and unexpected, are 

 apt to produce mental confusion or mental shock. And, 

 moreover, physical, as well as mental, effects may be pro- 

 duced by sounds which give rise to mental shock, as in the 

 case, mentioned by Sir David Brewster, of the dog that was 

 killed by the noise of artillery. A similar case has been 

 cited by Professor Adams. The animal, in the first case, was 

 startled from its sleep ; frightened by the unexpected sound, 

 it exhibited, we are told, an agony of fear, marked by tremor, 

 then hid itself and speedily died from the effect apparently 

 of combined mental and physical shock. 



The ' Animal World ' tells us of a certain pet dog that 

 was ' so nervous and sensitive as regards sudden noises that 

 a clap of thunder, the report of a gun, or even a loud sneeze 

 made her tremble for hours.' Thunder is an occasional 

 cause of panic in menagerie animals, and stampedes occur 

 in the wild quagga and gnu of Africa from unusual, supposed 

 danger-betokening or dreaded sounds. 



It is when, being stuck fast in a morass, the African ele- 

 phant is confused by the yelping of dogs, that the hunter can 

 venture to hamstring him (Livingstone). And it is amidst the 

 distracting yells of men and boys in the crowded city streets 

 that the poor footsore, overdriven ox first becomes bewil- 

 dered, and then excited, perhaps to reckless, dangerous fury. 



On the other hand, animals that are habituated to certain 

 kinds of sounds, are apt to be startled or alarmed by their 

 sudden stoppage. Silence the utter absence of sound when 

 this is unusual and unexpected, may produce the same effects 

 as discordant or terrifying noises. Thus the absence of an 

 accustomed footfall, the sudden entry into a room or me- 

 nagerie cage of a well-known and well-loved person, whose 

 footfall has not been previously heard, is apt to startle, 

 sometimes with a serious result (Bartlett). 



Certain smells are sometimes the cause or subjects of 

 marked antipathies on the part of certain animals, probably 



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