VOL. II.] PHILOSOPHICAL TRANSACTIONS. 243 



occasion of which the child's head and face were a little distorted, the whole 

 right side heing somewhat elevated and the left depressed, so that the passage 

 of his left ear was quite shut up, and that of the right ear proportionally dis- 

 tended and too open. This gentleman being for some time recommended to 

 my care, amongst other things, I spent some thoughts in searching the cause 

 of his deafness in the ear whose passage was open. And having found that the 

 auditory nerve was not perished, but that he could hear the sound of a lute- 

 string, holding one end thereof in his teeth, and had some perception of any 

 very vehement sound, I supposed the defect to lie in the want of due tension 

 of the tympanum of his ear ; whose use I took to be only to preserve the audi- 

 tory nerve and brain, and inward parts of the ear from outward injury by cold, 

 dust, &c. and to be no more to hearing than glass in the window is in a room 

 to seeing, i. e. as the one intromits light without cold or offence to those in 

 the room, so the other permits sound to pass ; and shuts out what else might 

 offend the organ ; as appears in the experiment of breaking the tympanum of a 

 dog, who hears never the worse for some few weeks, till other causes, as cold, 

 &c. vitiate the organ.* 



But for the free passage of the sound into the ear, it is requisite that the 

 tympanum be tense and hard stretched ; otherwise the laxness of that mem- 

 brane will certainly deaden and damp the sound. 



Now as to the case of the young gentleman before mentioned, I supposed 

 the requisite degree of tension of the tympanum to be wanting ; and that if by 

 any remedy it could be restored, I assumed that he might recover his hearing in 

 that ear : to which end, I advised his mother to consult with learned physicians. 



Mons. UAbbe Mariotte's^ new Discovery touching Vklon; with 

 Mons. Pecquet s Ansiver : both communicated hy Mons. Justel, 

 iV" 35, p. 668. 

 Having often observed in anatomical dissections of men as well as brutes, 



that the optic nerve does never answer just to the middle of the bottom of the 



* The fact here mentioned of the hearing being impaired in experiments made on dogs, a few 

 weeks after the perforation of the membrana t)'-mpanl, would be an objection to the modem 

 chirurgical remedy against deafness, (See Astley Cooper in the Phil. Trans, for ISOO and 1801) 

 were it not possible to counteract, in a great measure, the effects of cold and other injurious impres- 

 sions of the atmosphere, by wool or cotton occasionally introduced into the cavity of the ear. 



t Edmund Mariotte, an eminent French philosopher and mathematician, was bom at Dijon, and 

 died in the year l6S4. Mariotte became prior of St, Martin near Dijon, and a member of the 

 Academy of Sciences of Paris in l666, to which he communicated a number of curious and valuable 

 papers, which were printed in the collection of their memoirs in 1666, viz. from vol. i. to vol. x. 

 But all his works were collected into 2 vols. 4to, and printed at Leyden in 17 17. Mariotte was a 



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