54 



es.5'ay:s: and o b s er vat ion s 



SECT. VII. 



' On the ImperfeElion of our Knowledge 'coil' 

 ceming the Inflexions of Light. 



■ 51. Sir Ifaac Newton went a very confi- 

 flerable length in examining the inflexions of 

 light, as well as its reflexions and refradtions ; 

 but -did not bring his inquiry on this head to 

 a conclufion. He tells us, that he intended 

 once, if other bufinefs had not called him 

 off, to have made more experiments ; not for 

 confirming himfelf in preconceived opinions, 

 as many do ; but for difcovering the true 

 manner in which light is infleded, for pro- 

 ducing the coloured fringes with black lines 

 between them. He adds, however, fome 

 queries which contain hints of what he 

 had gathered on this fubjed from his own 

 obfervations, I'iz. that the rays of light differ 

 according to their colour in their degrees of 

 ■flexibility, and that they are bent feveral 

 tirries backwards and forwards with a fer- 

 •pentine motion in paffing by the fharp edges 

 of bodies : thefe thoughts he threw out " in 

 " order to incite others to a further fearch *.'■ 



But, 

 * AW/. Opt. p. 313. fee the firft two or three queries. 



