n^ HIGH DERIVATION. 241 



diffused matter, was the most diligent, careful, and original 

 astronomical observer of modern times. And the world 

 has not seen a more learned mathematician than the man 

 who, setting out with this conception of diffused matter, -• 

 concentrating towards its centre of gravity, pointed out^f 

 the way in which there would arise, in the course of; 

 its concentration, a balanced group of sun, planets, and 

 satellites, like that of which the Earth is a member. 



Thus, even were there but little direct evidence assign- 

 able for the Nebular Hypothesis, the probability of its 

 truth would still be strong. Its own high derivation and 

 the low derivation of the antagonist hypothesis, would to- 

 gether form a weighty reason for accepting it — at any rate, 

 provisionally. But the direct evidence assignable for the 

 Nebular Hypothesis is by no means little. It is far greater 

 in quantity, and more varied in kind, than is commonly 

 supposed. Much has been said here and there on this or that 

 class of evidences ; but nowhere, as far as we know, have 

 all the evidences, even of one class, been fully stated ; and 

 still less has there been an adequate statement of the sev- 

 eral groups of evidences in their ensemble. We propose 

 here to do something towards supplying the deficiency: 

 believing that, joined with the a priori reasons given above, 

 the array of a posteriori reasons will leave httle doubt in 

 the mind of any candid-inquirer. 



And first, let us address ourselves to those recent dis- 

 coveries in stellar astronomy, which have been supposed to 

 conflict with this celebrated speculation. 



When Sir William Herschel, directing his great reflec- 

 tor to various nebulous spots, found them resolvable into 

 clusters of stars, he inferred, and for a time maintained, 

 that all nebulous spots are clusters of stars exceedingly re- 

 mote from us. But after years of conscientious investiga- 

 tion, he concluded that " there were nebulosities which ^re 

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