Part II. in tbe C^E ATio^. 253 



the fetiforfn Coat reflefted, they are foon choak'd 

 in the black infide of the Uvea-, whereas were 

 they reflefted to and fro, there could be no di- 

 ftindt Vifion ; as we fee the Light admitted into 

 the dark Room we even now fpeak of, oblite- 

 rates the Species which before were {Qcn upon the 

 white Cloth or Paper. 



Fifthly, Becaufe the Rays from a nearer and 

 from a more remote Objedt do not meet ju ft in 

 the fame diftance behind the cryftalline Humour 

 (as may eafily be obferv'd in lenticular Glafs, 

 where the Point or Concourfe of the Rays from 

 a nearer Objeft is at a greater diftance behind the 

 Glafs, and from a farther at a lefler) therefore 

 the ciliary Procejes, or rather the Ligaments ob- 

 ferv'd in the infide of the fclerotick Tunicles of 

 the Eye by a late ingenious Anatomift, do ferve 

 inftead of a Mufcle, by their Contraftion to alter 

 the Figure of the Eye, and make it broader, and 

 confequently draw the Retina nearer to the cry- 

 ftalline Humour 5 and by their Relaxation fuffer 

 it to return to its natural diftance, according to 

 the Exigency of the Objed, in refpeft of Diftance 

 or Propinquity; and befides, poflibly the ciliary 

 Proceffes may, by their Conftriftion or Relaxa- 

 tion, render the Cryftalline it felf more gibbofe 

 or plain, and with the help of the Mufcles a lit- 

 tle alter the Figure of the whole Eye for the fame 

 reafon. To what I have faid might be ^dded, 

 that the retiform Tunicle is whitifli, for the bet- 

 "Ter and more trup Reception of the Species of 



Things ; 



