VOL. LXXXI.] PHILOSOPHICAL TRANSACTIONS. 27 



tint of their light, to produce which it would be required that the condensation 

 of the stars should be carried to an almost inconceivable degree of accumulation. 

 The surmise of the regeneration of stars, by means of planetary nebulae, ex- 

 pressed in a former paper, will become more probable, as all the luminous matter 

 contained in one of them, when gathered together into a body of the size of a 

 star, would have nearly such a quantity of light as we find the planetary nebulse 

 to give. To prove this experimentally, we may view them with a telescope that 

 does not magnify sufficiently to show their extent, by which means we shall gather 

 all their light together into a point, when they will be found to assume the ap- 

 pearance of small stars; that is, of stars at the distance of those which we call 

 of the 8th, Qth, or 10th magnitude. Indeed this idea is greatly supported by 

 the discovery of a well defined, lucid point, resembling a star, in the centre of 

 one of them : for the argument which has been used, in the case of nebulous 

 stars, to show the probability of the existence of a luminous matter, which rested 

 on the disparity between a bright point and its surrounding shining fluid, may 

 here be alleged with equal justice. If the point be a generating star, the fur- 

 ther accumulation of the already much condensed, luminous matter, may com- 

 plete it in time. 



How far the light that is perpetually emitted from millions of suns may be 

 concerned in this shining fluid, it might be presumptuous to attempt to deter- 

 mine; but, notwithstanding the unconceivable subtiity of the particles of light, 

 when the number of the emitting bodies is almost infinitely great, and the time 

 of the continual emission indefinitely long, the quantity of emitted particles may 

 well become adequate to the constitution of a shining fluid, or luminous matter, 

 provided a cause can be found that may retain them from flying ofi^, or reunite 

 them. But such a cause cannot be difficult to guess at, when we know that 

 light is so easily reflected, refracted, inflected, and deflected; and that, in the 

 inmiense range of its course, it must pass through innumerable systems, where 

 it cannot but frequently meet with many obstacles to its rectilinear progression. 

 Not to mention the great counteraction of the united attractive force of whole 

 sidereal systems, which must be continually exerting their power on the particles 

 while they are endeavouring to fly off". However, we shall lay no stress on a 

 surmise of this kind, as the means of verifying it are wanting; nor is it of any 

 immediate consequence to us to know the origin of the luminous matter. Let 

 it suffice, that its existence is rendered evident, by means of nebulous stars. 



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