do 



3\(aturall Hijlory^ 



' 1 ' 



DISSENT OFVISIBLES 

 and Audibles. 



268 '"T"* He Species of Vifibles feem to be EmiJJions of from the object 



1 / Almoft like Odours,fave that they are more Incorporeall : But 

 ■ the Species of Audibles feem to Participate more with LocaH Motion, 

 like Per cuff ions Jmprefjions made upon the Air. So that whereas all Bodies 

 do feem to work in two manners 5 Either by the Communication of their 

 Natures Or by the Imprejjions and Signatures of their Motions 5 The Dif- 

 fufionoi Species Vifible feemeth to participate more of the former Operation ; 

 and the Species Audible of the latter. 



269 The Species of Audibles feem to be carried more manfeftly thorow the 

 Air, than the Species of Vifibles : For (I conceive) that a Contrary ftrong 

 Wind will not much hinder the Sight of Vifibles, as it will do the Hear- 

 ing of Sounds. 



2 7° There is one Difference* above all others, between Vifibles and Audibles, 



that is the moft remarkable 5 as that whereupon many rinaller Differences 

 do depend : Namely, that Vifibles, (except Lights,) are carried in Right 

 Lines h and Audibles in Arcuate Lines. Hence itcometh to pafs, that Vifi- 

 bles do not intermingle, and confound one another, as hath been faid be- 

 fore 5 Bnt Sounds do. Hence it cometh, that the Solidity of Bodies doth 

 not much hinder the Sightifo that the Bodies be clear, and the Pores in 

 a Right Line, as in Glafs, Qiryftall, Diamonds, Water, dec. But a thin 

 Scarfe, or Handkerchiefe, though they be Bodies nothing fo folid, hinder 

 the Sight : Whereas (contrariwife) thefe Porous Bodies do not much hin- 

 der the Hearing, but folid Bodies do almoft flop it, or at the leaft attenu- 

 ate it. Hence alfo it cometh, that to the Reflexion of Vifibles, fmall GlalTes 

 fuffice, but to the Reverberation of Audibles, are required grater Spaces, as 

 hath likewife been faid before. 



271 Vifibles are feen further off", than Sounds are heard - 7 Allowing neverthe- 

 lefs the Rate of their Bignefi: For otherwife a great Sound will be heard 

 further off, than a Jmall Body ken. 



2 7 2 Vifibles squire (generally) fome Diftance between the objetf, and the 

 Etc, to be better feen Whereas in Audibles, the nearer the Approach of 

 the Sound is to the Senfe,the better.But in this there may be a double Errour. 

 The one becaufe to Seeing, there is required Light; And any thing that 

 toucheth the Pupill of the Eie (all over,) excludeth the Light. For I have 

 heard of a Perfon very credible, (who himfelf was cured of a Cataract in 

 one of his Eies,) that while the Silver Needle did work upon the Sight of 

 his Eie, to remove the Filme of the Catarael, he never faw any thing more 

 cleareor perfect, than that white Needle: Which (no doubt,) was, be- 

 caufe the Needle was leffer than the Pupill of the Eie, andfo took not the 

 Light from it. The other Errour may be, for that the object of Sight doth 

 ftrikeupon the pupill ot the Eie, directly without any interception •, whereas 

 the C^w of the doth hold off the Sound a little from the Organ: And 

 fo neverthelefs there is fome Diftance required in both. 



Vifibles are fwiftlier carried to the Senje, than Audibles ; As appeareth in 

 . ', Thunder' 



