VOL. LXXXI.] PHILOSOPHICAL TRANSACTIONS. IQ 



Cloudy or nebulous stars have been mentioned by several astronomers ; but 

 this name ought not to be applied to the objects which they have pointed out as 

 such ; for, on examination, they proved to be either mere clusters of stars, plainly 

 to be distinguished with his large instruments, or such nebulous appearances as 

 might be reasonably supposed to be occasioned by a multitude of stars at a vast 

 distance. The milky way itself consists entirely of stars, and by imperceptible 

 degrees he was led on from the most evident congeries of stars to other groups in 

 which the lucid points were smaller, but still very plainly to be seen ; and from 

 them to such wherein they could but barely be suspected, till he arrived at last to 

 spots in which no trace of a star was to be discerned. But then the gradations to 

 these latter were by such well-connected steps as left no room for doubt but that 

 all these phenomena were equally occasioned by stars, variously dispersed in the 

 immense expanse of the universe. 



When Dr. H. pursued these researches, he was in the situation of a natural 

 philosopher who follows the various species of animals and insects from the height 

 of their perfection down to the lowest ebb of life ; when, arriving at the vegetable 

 kingdom, he can scarcely point out to us the precise boundary where the animal 

 ceases and the plant begins ; and may even go so far as to suspect them not to be 

 essentially different. But recollecting himself, he compares, for instance, one of 

 the human species to a tree, and all doubt on the subject vanishes before him. 

 In the same manner we pass through gentle steps from a coarse cluster of stars, 

 such as the Pleiades, the Praesepe, the milky way, the cluster in the Crab, the 

 nebula in Hercules, that near the preceding hip of Bootes, the 17th, 38th, 41st 

 of the 7th class of his catalogues, the lOth, 20th, 35th of the 6th class, the 33d, 

 48th, ilSth of the 1st, the 12th, 150th, 736th of the 2d, and the 18th, 140th, 

 725th of the 3d, without any hesitation, till we find ourselves brought to an ob- 

 ject such as the nebula in Orion, where we are still inclined to remain in the once 

 adopted idea, of stars exceedingly remote, and inconceivably crowded, as being 

 the occasion of that remarkable appearance. It seems therefore to require a 

 more dissimilar object to set us right again. A glance like that of the naturalist, 

 who casts his eye from the perfect animal to the perfect vegetable, is wanting to 

 remove the veil from the mind of the astronomer. The object mentioned above 

 is the phenomenon that was wanting for this purpose. View, for instance, the 

 IQth cluster of the 6th class, and afterwards cast your eye on this cloudy star, 

 and the result will be no less decisive than that of the naturalist alluded to. Our 

 judgment will be, that the nebulosity about the star is not of a starry nature. 



But, that we may not be too precipitate in these new decisions, let us enter 

 more at large into the various grounds which induced us formerly to surmise, that 

 every visible object, in the extended and distant heavens, was of the starry kind, 

 and collate them with those which now offer themselves for the contrary opinion. 



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