358 Mr. Brougham's Experiments and Observations 
and the rays enter the sphere of reflexion, parallel and undecom- 
pounded. It is evident, therefore, that the effect arising from 
the different deflexibilities of the rays is destroyed by the equal 
and opposite effect produced by their different inflexibilities; 
and the same thing may in like manner be shewn to happen 
in the return of the rays from the body after reflexion. But 
let the rays be so reflected that they shall pass by the body 
without entering any more than one sphere of flexion ; then 
they will be separated by their flexibilities, as we before de- 
scribed. It appears, then, that if the rays of light were not 
differently reflexible, flexion could never produce the coloured 
images, by separating the compound light. And, indeed, this 
may be easily proved by fact. At 144 feet from the bending 
body, the greatest fringes by flexion are only half an inch in 
length, whereas the fourth or fifth images by reflexion are 
above half an inch at one foot from the reflecting surface : the 
one sort is therefore more than 144 times more distended than 
the other, whereas the flexion could, at the very farthest, only 
double them. Also the distinctness, and brightness, and re- 
gularity of the colouring, are quite different in the two cases ; 
the supposed cause would neither account for the order of the 
colours, nor for their absence in common specular reflexion, 
and refraction through two prisms joined together with their 
angles the contrary ways. Lastly, if we suppose the images to 
be produced by flexion, and then reflected from the body, it 
would follow that light incident on a prism should be decom- 
pounded, formed into several coloured images, and then re- 
fracted, the violet being least and the red most bent ; all which 
is perfectly the reverse of what actually happens. I have mul- 
tiplied the proof of this proposition perhaps beyond what is 
