228 Mr . Brougham's Experiments and Observations on 
opinion, with respect to matter of theory that is in dispute, 
will, it is more than probable, influence us in the manner of 
drawing our conclusions, and even in the manner of recording 
the experiments that lead to these, I have endeavoured as 
much as possible to keep in view the saying of the Brahmin : 
“ that he who obstinately adheres to any set of opinions, may 
“ bring himself at last to believe that the fresh sandal wood is 
“ a flame of fire." * 
Part I. Of Flexion. 
In order to fix our ideas on a subject which has never been 
treated of with mathematical precision, we shall suppose, for 
the present, that all the parts of light are equally acted upon 
in their passage by bodies ; and deduce several of the most 
important propositions which occur, without mentioning the 
demonstrations. 
Def l. If a ray passes within a certain distance of any 
body, it is bent inwards ; this we shall call Inflection. 2. If 
it passes at a still greater distance it is turned away ; this may 
be termed Deflection. 3. The angle of inflection is that which 
the inflected ray makes with the line drawn parallel to the 
edge of the inflecting body, and the angle of incidence is that 
made by the ray before inflection, at the point where it meets 
the parallel. And so of the angle of deflection. 
Proposition I. The force by which bodies inflect and deflect 
the rays acts in lines perpendicular to their surfaces. 
Prop. II. The sines of inflection and deflection are each of 
them to the sine of incidence in a given ratio ; (and what this 
ratio is we shall afterwards shew). 
* Asiatic Researches i _Vol. I. p. 224. 
