Manchester Memoirs, Vol. Hi. (1908), No. 10. 7 



impenetrable, moveable Particles, of such Sizes and Figures, 

 and with such other Properties, and in such Proportion to 

 Space, as more conduced to the End for which he form'd them ; 

 and that these primitive Particles being Solids, are incomparably- 

 harder than any porous Bodies compounded of them ; even so 

 very hard as never to wear or break in pieces : No ordinary 

 power being able to divide what God himself made one in the 

 first Creation, While the Particles continue entire, they may 

 compose Bodies of one and the same Nature and Texture in all 

 Ages : But should they wear away, or break in pieces, the 

 Nature of Things depending on them would be changed. 

 Water and Earth composed of old worn Particles and Fragments 

 of Particles, would not be of the same Nature and Texture now, 

 with Water and Earth composed of entire Particles in the 

 Beginning. And therefore that Nature may be lasting, the 

 Changes of corporeal Things are to be placed only in the 

 various Separations and new Associations and Motions of these 

 permanent Particles : compound Bodies being apt to break, not 

 in the midst of solid Particles, but where those particles are laid 

 together and only touch in a few Points. 



" It seems to me farther, that these Particles have not only a 

 Vis inertiae, accompanied with such passive Laws of Motion as 

 naturally result from that Force, but also that they are moved 

 by certain active Principles [Energies], such as that of Gravity, 

 and that which causes Fermentation, and the Cohesion of 

 Bodies. These Principles I consider not as occult Qualities, 

 supposed to result from the specifick Forms of Things, but as 

 general Laws of Nature, by which the Things themselves are 

 form'd ; their Truth appearing to us by Phaenomena, though 

 their Causes be not yet discover'd. For these are manifest 

 Qualities, and their Causes only are occult " 



This survey carries us about as near as purely physical 

 speculation, based on the broad simple principles of 

 universal dynamics that Newton was the first definitely to 

 codify, could approach towards an atomic theory. And 

 it is a considerable advance. The uninstructed tendency, 

 judging from one's own early recollection, is to assume 



