PHYSICAL AND LITERARY. 85 



to the greateft diftances, viz. if the rays are 

 always put into a new fit of moji eafy tranf- 

 miffion at entering every new pore or particle. 

 But is not that fuppofition contrary to what 

 Sir Ifaac teaches el fe where ; That the fits of 

 reflexion and tranfinifiion continue to return 

 at equal intervals, after a ray has entered a 

 tranfparent body, and are thus regularly pro- 

 pagated to the greateft diftances*? And, if 

 this be true, how can the rays be tranfmitted 

 to any fenfible diftance, fince they mufl 

 often arrive in fits of eafy reflexion at the 

 common furfaces of pores and particles ? But, 

 altho' it could be underftood by the dodrine 

 of the fits in light why there is no reflexion 

 from the interior parts of water and other 

 pellucid mediums f , does not the redlilinear 

 tranfmiffion of light thro' thefe bodies in all 

 directions, and confequently in all degrees of 

 obliquity, to their internal parts, prove, that 

 thefe parts, upon account of their minutenefs, 

 lofe their powers of refra(5tion as well as 

 reflexion ? And to what known property of 

 light or bodies can this be attributed ? 



QuER. 



* Nezvt. Opt. Book ii. part 2. prop. 12. 

 •}• Ibid. Book ii, part 3. prop. 4. 



