84 ESSAYS AND OBSERVATIONS 



QuER. XXII. If the fits are produced by 

 an alternate acceleration and retardation of 

 the particles of light, fome of the particles, 

 which are fwift enough to be tninfmitted at 

 the firil: furface of a tranfparent tnediiim^ muft 

 overcome the refleding power more eafily 

 than others ; namely, thofe that happen to 

 be in their point of greateft celerity or 

 neareft to it : Now, muft not rays that are 

 moving with different velocities be different- 

 ly bent from their courfe, as we argued 

 above with refpe(!^ to fimple-coloured rays, 

 by the fame refractive power ? Why there- 

 fore is not every beam of light, homogeneal 

 or heterogeneal, diffufed by refradion into 

 innumerable rays, according to the refpe- 

 dive velocities with which they entered the 

 refrading furface ? Is it a fufficient anfwer 

 to this query, That rays which are fartheft 

 from their point of greateft fvviftnefs will be 

 moft bent in a diredion contrary to that of 

 refradion, by the refieding power, and will 

 therefore only return to the diredion of 

 fwifter rays by a greater degree of refradion ? 



QuER. XXIII. Sir I/d tic NeivtoT? j\ji{{\y ^r- 

 gues, that lis^ht muft be refleded at a diftance 

 fipm bpdies3 becaufe the moft poliflied fur- 

 faces 



