160 Mr. Home's additional Remarks, &c. 



That sounds can be communicated with accuracy by the bones 

 of the skull, to the internal organ, when received from solid or 

 liquid substances, has long been well understood. 



That the membrana tympani is incapable of perfectly an- 

 swering this purpose, when sounds are propagated through air, 

 has-been a generally received opinion ; to refute which, was the 

 object of my former paper. That, in cases in which the mem- 

 brana tympani has been destroyed, the air is capable of acting 

 with sufficient force upon the stapes to communicate vibrations 

 to it, and to produce on the internal organ the necessary effect 

 for perfect hearing, is completely ascertained by Mr. Cooper's 

 observations. 





