122 OBSERVATIONS ON VENTRILOQUISM. 



quelin. He therefore concludes, that the natural magnefian 

 borate, when perfectly tranfparent, does not contain lime, and 

 that that which is found in opake cryftals is interpofed in the 

 ftate of carbonate, and caufes their opacity. 



This fubftance muft not therefore any longer be confidered 

 as a triple fait, under the name of magnefio-calcareous borate, 

 but fimply that of magnefian borate. 



Bulletin des Sciences . No. 60. 



XIV. 



Fudts and Obfervations tending; to explain the curious Phenomenon 

 of Ventriloquifni. By Mr. John Gouch *. 



The power of 1 N the excellent Paper from which I have extracted the fol- 

 diftinguiiWng lowing pages, the author begins by obferving, that the power 

 found has been or " tne ear to diftinguifh very flight variations of tone has long 

 long confidered j been a fubject of univerfal notice ; but that anothor very re- 

 direction, markable power, namely that of afcertaining the direction of 

 found, remains ftill without explanation. We perceive not 

 only the tone, intenfity, and character of found j but alfo whe- 

 ther it arrives from the right or the left, from above or below, 

 and this with a degree of precifion which is of great and emi- 

 nent utility in the concerns of life. 

 All founds arrive To inveftigate the foundation of this habitual judgment, we 

 in the ear from canno t have recourfe to analogy of the fenfe of hearing with 

 t i on# ' that of virion. The Iail direction of the ray of light is phyfi- 

 cally impreffed by the pencil which enters the organ of that 

 fenfe : but in the ear the undulations of found are all made to 

 ftrike the inftrument of perception in the fame direction, 

 namely that of the auditory palTage. The author, therefore, 

 Our knowledge is led to attend to other facts and obfervations. He found by 

 tf fcudfees* ex P eriment - with an inflrument confiruaed to afford the fame 

 not depend on equal found by blows from the action of a fpring, ' that he could 

 the impulse in judge of an increafe or diminution of diitance, to the one hun-r 



theear: but on J . & . . , ". . , , ' ,. 



other facts. dred and twentieth part ot the whole range. He alfo remarks, 

 Statement. 



* Partly abridged and partly extracted from his " Investigation 

 " of the Method whereby Men judge by the Ear of the pofition of 

 " Sonorous Bodies relative to their own Perfons.'" Manehefter 

 Memoirs, vol. V. part 2, page 622. London, 1802. 



that 



