94 STATEMENTANDEXPOSITIONOF 



gaseous or vaporous ' nebulous matter,' it loses little or none of its force." [The 

 spectroscope indicates that that need not always be.] " Subsidence, and the central 

 aggregation consequent on subsidence, may go on quite as well among a multitude 

 of discrete bodies under the influence of mutual attraction, and feeble or partially 

 opposing projectile motions, as among the particles of a gaseous fluid." 



"(872) The ' nebular hypothesis,'' as it has been termed, and the theory of sidereal 

 aggregation stand, in fact, quite independent of each other, the one as a physical 

 conception of processes which may yet, for aught we know, have formed part of 

 that mysterious chain of causes and effects antecedent to the existence of separate 

 self-luminous solid bodies ; the other as an application of dynamical principles to 

 cases of a very complicated nature no doubt, but in which the possibility or impos- 

 sibility, at least, of certain general results may be determined on perfectly legiti- 

 mate principles." 



"Among a crowd of solid bodies of whatever size, animated by independent and 

 partially opposing influences, motions opposite to each other oimst produce colli- 

 sion, destruction of velocity, and subsidence or near approach towards the center 

 of preponderant attraction; while those which conspire or remain outstanding 

 after such conflicts, must ultimately give rise to circulation of a permanent 

 character. Whatever we may think of such collisions as events, there is nothing 

 in this conception contrary to sound mechanical principles." 



"Ages which to us may well appear indefinite may easily be conceived to 

 pass without a single instance of collision, in the nature of a catastrophe. Such 

 may have gradually become rarer as the system has emerged from what must be 

 considered its chaotic state, till at length, in the fulness of time, and, under the 

 pre-arranging guidance of that design which pervades universal nature, each indi- 

 vidual may have taken up such a course as to annul the possibility of further 

 destructive interference." 



To which we may add, that it is well understood, that, with respect to all this. 

 Sir J. Herschel has but fully and clearly expressed the very thoughts and feelings 

 of his distinguished father. 



[The supposed " aggregation," in view of what is stated in Note (A), must be 

 regarded as being a wider segregation, by the continuance of an even now pro- 

 gressive dispersion.'\ 



In so far as the nehular hypothesis here under consideration, has, at least, the 

 character of an ingenious conjecture in the form of a generalization, it would seem 

 to relate to a more ancient state of things than that contemplated in our Note (A) ; 

 being indicative of the way in which the rotating spheroids there described might 

 themselves have been formed. 



The existing phenomena seem to require the spheroids to have preceded the 

 present state of things ; but there is very little to indicate what must have been 

 the state of the material composing the spheroids before they acquired their form. 



The revelations by the spectroscope of a similarity of molecular constitution in 

 so very many instances are not indeed inconsistent with the supposition of a common 

 origin ; yet they do not require that. 



The statement of Sir J. Herschel, already quoted, speaks of the "chain of causes 



