Newton, Leibnitz, and Boscovich to the Atomic Theoi-y. 59 



or atomosphere lohick is inert and elastic, which is retained by its intrinsic 

 attractiveness o?' contractility/ around the centre, and is subject to be actuated 

 by heat and polarity. 



Of Gkavitation. 



VII. Moreover, if elements or masses thus tending towards each other 

 be considered merely as elements or masses existing in different regions 

 of space, and tending towards each other in consequence of this difference 

 of position, the law of assimilation in giving the phenomenon gives also 

 its law. Thus, in reference to each centre of force, the tendency or 

 attractive power in the various concentric shells that exist around that 

 centre must, under that law, be assimilated in all. These must all 

 be equal in this respect. Each considered in its totality, must be 

 isodynamic, whether the surface of that particular spherical shell be 

 small, because it lies near the centre, or large, because it is more 

 remote from the centre. Now, these spherical shells or surfaces which 

 thus, under the law of assimilation, must be isodynamic, vary directly 

 as the square of their distance from the centre. The value of each, 

 therefore, considered as a force, when estimated in terms of the distance, 

 must vary inversely as the square of the distance. And thus we obtain 

 the law of gravitation, not only to the extent generally admitted, but as 

 that by which all things are brought and kept together, and in relation 

 with each other, from the inconceivably mmute atomosphere of the least 

 elements of the material system to the orbit of Neptune, and we know not 

 how far beyond. And thus our single law applied to that which, when 

 postulated, is next to nothing without it and merely something, and as 

 fast as thought can proceed, gives as its successive manifestations inertia, 

 elasticity, repulsion, heat, polarity, attraction, gravitation ; and thus 

 imparts a scientific homogeneity to properties, some of which have been 

 hitherto regai'ded as quite heterogeneous and unrelated to the others 

 except in so far as they are co-existent in the same subjects. Nor this 

 only. It exhausts inquiry respecting them. It withdraws them from 

 the position of mere data of nature, merely unaccountable or ultimate 

 facts. It gives their genesis out of a single principle. It remains only 

 for those who are competent to conceive the subject better, and to con- 

 struct a calculus whose simplest functions shall express these facts and 

 relations on which all the movements of Nature depend. 



Elements of Mobphology. 



Our synthesis, however, does not terminate here. We have, in fact, 

 only reached as yet the conception of matter, as it manifests itself to us 

 iu the most remote regions, wliether those in which the least elements 



