the Inflection , Reflection , and Colours of Light . 277 
Prop. VIII. The sines of reflection of the different rays are 
in given ratios to those of incidence (which are determined in 
the paper.) 
Prop. IX. The ratio of the sizes of the different parts of 
light are found. 
Prop. X. The colours of natural bodies are found to de- 
pend on the different reflexibilities of the rays, and sometimes 
on their flexibilities. 
Prop. XI. The rays of light are reflected, refracted, in- 
flected, and deflected, by one and the same power, variously 
exerted in different circumstances. 
