APPENDIX A LUI 



us by Dalton as ultimate particles, as atoms, has been proved by Prof. 

 J. J. Thomson of Cambridge; and the so-called atoms themselves are 

 found to be complex systems masquerading as simple bodies; and 

 are indeed gigantic impostors compared with their little successors, 



Newton and Wilson. 



But this does not detract from the genius and merit of Dalton, for 

 which Wilson expresses great admiration, and is so far carried away that 

 he does, unwittingly, a great injustice to Newton. 



In contrasting the earlier views of the Atomic Theory with those of 

 Dalton he takes Newton as representative, and quotes from the fourth edi- 

 tion of his "Opticks" as follows : — "All things considered" says Newton, 

 *•' it seems probable that God in the beginning, formed matter in solid, 

 ^•' massy, hard, impenetrable, movable particles of such sizes, figures, 

 " and with such other properties, and in such proportion to space, as 

 "most conduced to the end for which he formed 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 to pieces, no ordinary power being able to divide what God 

 '•' made one in the first creation.*' 



On this extract "Wilson remarks: — 



" Newton, it will be observed, says nothing concerning the weight of 

 "' his primitive particles." — " It is here that Dalton introducing the 

 "- question of weight, leaves Newton behind, and takes not a step, but 

 '' a stride, in advance of all previous speculators on atomics." 



Wilson has overlooked the word " massy," i.e. having mass, chosen 

 carefully by Ne-wton, and a very mucli better word in one respect than 

 " Aveighty " or any other referring to weight, for if these " primitive 

 particles" were removed to the Sun or any of the heavenly bodies or 

 even to different parts of the Earth their weight would change, while 

 their mass would be unchanged. Newton had proved by experiments 

 that at a given place mass was proportional to weight (a fact ignored by 

 many approved text-books on Mechanics in Wilson's time). That the 

 omission by Newton of weiglit from the essential properties of particles 

 was deliberate is seen by reference to the " Eegulœ Philosophandi" where 

 he states, repeats, and re-iterates the five properties, extension, hardness, 

 impenetrabilitv', mobility, and "vis inertiœ ;" subsequently saying that he 

 b}^ no means affirms ("minime affirmo") that gravity is essential to bodies, 

 but " vis inertias " or " vis insita " as it is elsewhere called, is immu- 

 table. This " vis insita " he states in the Definitions is always propor- 

 tional to the mass. It mav also be noted that Newton does not use the 



