PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 727 



A.nd let me add: No beginning, no end, but eternal transition, 

 one form developing another form, one universe devel'oping another 

 universe, for ever and ever from eternal matter, forever and ever 

 by eternal force, eternal by that Power which governs the motions 

 of constellations and galaxys, and also the emotions of the poor 

 human heart, transitorily imprisoned on the surface of some little 

 planet like ours. 



The following paper was read by H. F. Walling, Esq., which com- 

 pletes the discussion commenced by the first paper of Professor 

 Grimes: 



The Nebular Theory. 



. The results of all inquiries into the origin of the earth and other 

 planets and stars must, in the present condition of scientific know- 

 ledge be more or less speculative in their character, and, as has 

 been properly remarked during the discussion of this subject, cor- 

 rect theories can only be formed when the observedyac^s are suffi- 

 ciently numerous to fully establish them. In the meantime, those 

 hypothesis which best explain all the known facts, and which at 

 the same time include the greatest number of them under simple 

 and general laws, aref most likely to be finally established and to 

 lead to the discovery of other facts which might otherwise elude 

 our observation. 



The Nebular theory of La Place seems to be one of this descrip- 

 tion, and for that reason has met with very general favor among 

 scientific men. In the paper which w^as lately read before this 

 association by Mr. Wood, the arguments in opposition to the 

 nebular theory, or more especially to that portion of it which sup- 

 poses the earth to have been in a state of fluidity and perhaps to 

 still continue so internally, seem to me to be entirely fallacious, 

 I propose briefly to point out its fallacies, without attempting to 

 produce any new arguments in favor of the controverted theory, 

 or of the fluidity of the earth, as this has been rendered unneces- 

 sary by the full and able manner in which it has already been 

 explained and advocated. 



It is hardly necessary to controvert the first argument of Mr. 

 Wood, that, since force cannot exist independently of matter, no 

 condensation of nebulas could have taken place, because the con- 

 sequent radiation of heat into space where there was nothins^ to 

 receive it would be impossible. This argument would apply with 

 equal weight against the well known facts that the earth and all 

 bodies upon it radiate heat freely into space, as may be made 



