But to proceed, the same kind of _obliquity_ of the Pulses and Rays will happen also when the refraction is made out of a more easie into a more difficult _mediu_; as by the calculations of GQ & CSR which are refracted from the perpendicular. In both which calculations ’tis _obvious_ to observe, that always that part of the Ray towards which the refraction is made has the end of the _orbicular pulse_ precedent to that of the other side. And always, the oftner the refraction is made the same way, Or the greater the single refraction is, the more is this unequal progress. So that having found this odd propriety to be an inseparable concomitant of a refracted Ray, not streightned by a contrary refraction, we will next examine the refractions of the Sun-beams, as they are suffer’d onely to pass through a small passage, _obliquely_ out of a more difficult, into a more easie _medium_. Let us suppose therefore ABC in the second Figure to represent a large _Chemical Glass-body_ about two foot long, filled with very fair Water as high as AB, and inclin’d in a convenient posture with B towards the Sun: Let us further suppose the top of it to be cover’d with an _opacous_ body, all but the hole ab, through which the Sun-beams are suffer’d to pass into the Water, and are thereby refracted to cdef, against which part, if a Paper be expanded on the outside, there will appear all the colours of the Rainbow, that is, there will be generated the two principal colours, _Scarlet_ and _Blue_, and all the _intermediate_ ones which arise from the composition and dilutings of these two, that is, cd shall exhibit a _Scarlet_, which toward d is diluted into a _Yellow_; this is the refraction of the Ray, ik, which comes from the underside of the Sun; and the Ray ef shall appear of a deep _Blue_, which is gradually towards e diluted into a pale _Watchet-blue_. Between d and e the two _diluted_ colours. _Blue_ and _Yellow_ are mixt and compounded into a _Green_; and this I imagine to be the reason why _Green_ is so acceptable a colour to the eye, and that either of the two extremes are, if intense, rather a little offensive, namely, the being plac’d in the middle between the two extremes, and compounded out of both those, _diluted_ also, or somewhat qualifi’d, for the _composition_, arising from the mixture of the two extremes _undiluted_, makes a _Purple_, which though it be a lovely colour, and pretty acceptable to the eye, yet is it nothing comparable to the ravishing pleasure with which a curious and well tempered _Green_ affects the eye. If removing the Paper, the eye be plac’d against cd, it will perceive the lower side of the Sun (or a Candle at night which is much better, because it offends not the eye, and is more easily manageable) to be of a deep _Red_, and if against ef it will perceive the upper part of the luminous body to be of a deep _Blue_; and these colours will appear deeper and deeper, according as the Rays from the luminous body fall more