37 6’ Mr . Brougham's Experiments and Observations 
most, those which are reflected have the red outermost; the 
former are the colours arranged as they would be by inflexion, 
the latter as they would be by deflexion ; and here by outer- 
most and innermost must be understood relative position only, 
or position with respect to the thickness of the plate, not of 
the central spot. Secondly, the thinnest plate makes the broad- 
est ring (the diameter of the rings being in the inverse subdu- 
plicate ratio of the plate's thickness); just so is it with fringes 
by flexion; nearer the body the fringes are broadest, and their 
diameters increase in the same ratio with the diameters of the 
rings by plates whose thickness is uniform ; each distance from 
the bending body therefore corresponds with a ring or fringe 
of a particular breadth, and the alternate distances correspond 
with the dark intervals : the question then is, what becomes of 
the light which falls on or passes at these alternate distances ? 
In the case of thin plates, this light is transmitted in other 
rings ; we should therefore be led to think that in the case of 
the light passing by bodies, it should be at one distance in- 
flected, and at another deflected ; and in fact the phasnomena 
agree with this, for fringes are formed by inflexion within the 
shadows of bodies ; they are separated by dark intervals ; the 
fringes and the intervals without the shadow decrease in breadth 
according to the same law ; so that the fringes and intervals 
within the shadow correspond with the intervals and fringes 
without, respectively. Nor will this explanation at all affect 
the theory formerly laid down; it will only (if found consistent 
with farther induction) change the definite spheres of inflexion 
and deflexion into alternate spheres. At any rate, the facts here 
being the same with those described by Newton, but in diffe- 
rent circumstances, teach us to reconcile the difference, which 
