420 Dr. Wells’s Observations and Experiments 
When Sir Isaac Newton began his experiments upon light 
and colours, it was generally believed, that colours in opake 
bodies arise from some modification given to light, by the 
surfaces which reflect it. In opposition to one part of this 
opinion, our great philosopher maintained, that such bodies are 
seen coloured, from their acting differently upon the different 
colorific rays, of which white light is composed ; but having 
established this point beyond dispute, he seems to have ad- 
mitted, without inquiry, that colours are produced at the sur- 
faces of the opake bodies to which they belong. For his expe- 
riments do not necessarily lead to such a conclusion ; on the 
contrary, they are not more consistent with it, than they are 
with the opinion of Kepler and Zucchius. This opinion, 
indeed, he appears not to have known ; since he has taken for 
granted, what is contradicted by the experiments upon which 
it is founded, that the tinging particles of transparent bodies 
reflect coloured light. * 
The very splendour of Sir Isaac Newton’s discoveries in 
optics, has probably done some injury to this branch of know- 
ledge ; for soon after they were made public, it became a 
common opinion, that the subject of light and colours had 
been exhausted by that great man, and that no writer upon it 
before him, was now worthy of being read. The former part 
of this opinion has long been generally acknowledged to be 
unjust ; but the latter part of it is still maintained by many. 
telescope; but his book was printed in 1652, eleven years before the publication of the 
“ Optica Promota” of James Gregory. I have not met with any account of Zuc- 
c h 1 us, in Montucla’s or Priestley’s histories; in the article “ telescope,” in 
the French Encyclopedia; or in any biographical dictionary which I have consulted. 
* Optics, Book i. Part II. Prop. 10. 
