NEBULAR HYPOTHESIS. 13 



and again in a condition proximate to pure stars ; the only 

 remaining point has reference to nebulae in an intermediate 

 state, — when the roundish masses seem to have begun a pro- 

 cess of organization or concentration, and carried it onwards 

 through several stages : — a state to which we have every 

 variety of analogon in the various forms and densities of 

 cometic nuclei. Sir William Herschel certainly was not 

 ignorant that round or spherical clusters abound in the skies, 

 which, when first seen, present all the appearances of such 

 nebulae — nay, he grounded on the fact of their approximate 

 sphericity and varying degrees of concentration, some of the 

 boldest and most engrossing of his conjectures ; nor would 

 he have doubted that multitudes which, even to his instru- 

 ments, seemed only general lights, would, in after times, be 

 resolved ; but here, as before, the gist of the question is not, 

 can you resolve round nebulae never resolved before ; but can 

 you resolve such as, quite within the range of former vision, 

 have continued intractable under the scrutiny of powers 

 which, judging from the average of our experience, must 

 surpass what ought to have resolved them ? 



" Such are my views as to the present condition of this im- 

 portant question ; and if they are correct, it ^vill appear that, 

 notwithstanding the resolutions achieved by the new instru- 

 ments, they are, as yet, quite as likely — by accumulating 

 new objects belonging to the three foregoing classes, and by 

 more surely and distinctly establishing their characteristic 

 features — to strengthen, as to invalidate the grounds of the 

 nebular hypothesis. Eagerly, but patiently, let us watch the 

 approaching revelations." 



Various minor objections have been presented 

 to the nebular hj-pothesis ; but, before adverting 

 to any of them, I may give a brief abstract of cer- 



