PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 655 



1st. The impossibility, reasoning from known foots or experi- 

 ments, of mcatter being so attenuated as to fill all space. 



2d. If so attenuated, it remains to be proved that there would 

 be many or even one centre of gravity. 



3d. That if attenuated and heated to so high temperature, there 

 would be no commingling of gases, as is shown by experiment. 



4th. We have no reason to suppose that molecules of matter aro 

 endowed with motion of any kind. Unless moved upon by a force 

 outside of themselves, they are quiescent. 



5th. We know the force called gravitation, but know not the 

 primum mobile of the centrifugal force, or of the rototary force. 

 All is here mere assumption. 



6th. While the theory explains very well the movements of 

 most of the heavenly bodies, it fails to account for the eccentric 

 movement of Uranus and Neptune, and the movement of the moons 

 of Uranus. 



7th. It fails to account for the eccentric course of the comets, 

 and their unequal rapidity of movement. 



8th. It is opposed to all our present knowledge of matter, which 

 we have reason to believe is but a reappearance of itself, in succes- 

 sive phases or rounds of phenomena, manifested by chemical 

 cJianges and reactions. 



The speaker then alluded to the changes which had occurred on 

 the earth, asserting that land always had an existence since the 

 creation; that it had been slowly upheaved at irregular periods, 

 although limited areas may after have risen suddenly or spasmodi- 

 cally. He quoted the opinion of E. B. Hunt, Kane and Bache 

 regarding ocean currents, and concluded by saying that the his- 

 tory of the earth would be embraced in four volumes. The latest 

 and most complete is "its geography." The next preceding is 

 " its geology," of which much is written and much remains to he 

 written. The next, "its physical changes," or the operation of 

 forces which first defined its form. This is yet to be furnished by 

 the mechanician and dynamical philosopher. The fourth, "its 

 chemical changes," is mainly unwritten, although such able writers 

 as Hunt, of Canada, Bischoff, of Germany, and Daubree, of France, 

 had contributed largely to it. The completion of this volume 

 ofiers the grandest field to living chemists. It must be accom- 

 plished neither by shrewd guessing nor by assumption, but only 

 by patient labor, and by generalization from a multitude of expe- 

 riments. 



