244 Mr. Brougham's Experiments and Observation? or. 
effervescence took place, by the escape of fixed air, w ! -e 
in bubbles through the tube ; and looking at the candle tl »ugh 
one of these, I saw the images formed with the colours still 
in the same order, but a little larger than before. 
We are now to see to what conclusions these experiments 
lead us. — The first experiment shows, that all sorts of light, 
whether direct, or reflected, or refracted, produces colours by 
reflection from a curve surface. From the second we learn, that 
these colours are distinct images or spectra of the luminous 
body, much dilated in length, but not at all in breadth ; and that 
theangleof incidence beingchanged, thedilatationof the images 
is also changed : and from the third experiment it appears, 
that each full image is composed of seven colours; red, orange, 
yellow, green, blue, indigo, and violet ; and that the proper 
order is red outermost, and violet innermost, the rest being in 
their order. The fourth experiment shows, that these images 
are produced, not by any accidental or new modification im- 
pressed on the rays, but by the white light being decomposed 
by reflection ; that the mean rays, or those at the confine of 
the green and blue, are reflected at an angle equal to that of 
incidence, and the red at a less, the violet at a greater angle. 
Experiments 5th and 6th prove, beyond a doubt, the decom- 
position and separation of the rays by reflection ; for in both 
we see that the colours in the images are those, and those only, 
which were mixed in the ray by reflection or refraction, before 
and at incidence, whilst the 6th is (in addition) a proof that 
all the rays of any one image, if mixed together, compound a 
beam exactly similar to the beam that was at first decom- 
pounded. The 7th experiment shows, that the colours into 
which the rays are separated by reflection are homogeneous 
