PHYSICAL AND LITERARY. 55^ 



SECT. VIII. 

 J / 



^erieSy confifiing of Doubts^ Difficulties, and 



Conje5iureSy concerning Lights Colours^ and 



coloured Bodies. 



Query I. Are not the rays, emitted by 

 all forts of luminous bodies, fimilar to thofe 

 of the fun, both as to colour and degrees of 

 refrangibility ? And, do not luminous bo- 

 dies differ from one another only according 

 to the colours which they emit moft plenti- 

 fully, in like manner as opaque bodies are 

 diftinguiOied by the colours of incident light 

 which they refled: in greatell abundance ? 

 {See N° 24, 25, 26, 27, 28, and 29.J But, 

 to make our indudion fufficiently ftrong, 

 ought not experiments to be made with the 

 lights of a greater variety of bodies? And 

 would it not further conduce to the illuftra- 

 tion of this queftion to form, by Sir Jfaacs 

 method *, a beam of folar light, confifting 

 of luch colours and in fuch proportions as 

 were feen in the lights of falts and burning 

 fpirits ; and then to obferve in it the appear- 

 ance 



* NeiAJt. Opt. took I. part 2. prop. 11. 



