1 30 Mifcettanea Curio fa. 



Otacoufiickj here come in for helping the Ear \ 

 which may be Co contriv'd (by a right under- 

 ftanding the Progrejfion of Sounds, which is the 

 principal thing to be known for the due regula- 

 ting all fuch kinds of Inftruments) as that the 

 Sound might enter the Ear without any Refra&i- 

 on, but as now they are generally made I refer 

 them to B^ef railed Audition* 



x. As to the Medium, I know not how that, 

 by any contrivance of Art, can advantage D*- 

 re # Hearing* otherwife than I have declar'd alrea-jj 

 dy in the propagation or conveyance of Sounds, 

 though to the Refracting or Reflecting of them 

 it may very much conduce \ of which prefent- 



And fb 1 have done with the fir A: part of my 

 prefent undertaking, which is the Comparifon of 

 Diretl Vifion and Audition, as to their Improve- 

 ments from Art. The reft follow. Where- 

 fore, 



II. Concerning fyfra&cd Vifion and its Com- 

 panion, I obferve, That RgfraBed Vifion is al- 

 ways made Ex parte Medii, as I{efle8ed is ex 

 parte ObjeHi. And therefore, though DireB Vifion 

 maybe help'd ex parte Obje&i, Medii vel Organi, 

 yet fyfratted can be improv'd only ex parte Me- 

 dii, and Reflected ex parte Corporis oppofiti alone, 

 tlnlefi it be in-a mixt or compound Vifion, that 

 is %efra&o-f{efiext, when the rcflext Rays pafs 

 to the Eye through a refracting Medium, fuch 

 as the Medium Internum, contain'd in the Body 

 of the Eye, always is. So that in truth, all 

 Vifion is Hefrattedhy an internal Refraction made 

 in ipfo Qculo, 



And 



