THE ATOMIC VIEW OF NATURE. 



451 



atomic theory could not rest contented with a knowledge 

 of the relative weights of elementary atoms, but would 

 have to be completed by a geometrical conception of the 

 arrangement of the elementary particles in all the three 

 dimensions of solid extension." ^ 



But though a further development of the atomic view, 

 not only " pondere " but also " mensura," may be expected 

 in the near future, the progress of chemistry, which has 

 benefited so much by this view of nature, will not de- 49. 



Defects and 



pend exclusively upon this line of thought, nor perhaps insufficiency 

 to so large an extent as it has done during the greater atomic view, 

 part of the century. We have seen how the atomic 

 theory of Dalton rose to the position of being more 

 than a convenient symbolism, and how it became a 

 physical theory of matter and of nature mainly by 

 the support which it received from a different line of 

 reasoning. 



The development of this line of reasoning led to the 

 employment of the statistical method, a view quite 

 foreign to other branches of physical science. 



The kinetic theory of gases itself had been elaborated 

 in connection with still another line of reasoning, with 

 the endeavour to get a clearer and more comprehensive 

 view of the nature of the different forces which the 

 astronomical as well as the atomic views had merely 

 accepted as given quantities without further examination. 

 We are thus necessarily led on to trace the history of 



1 See WoUastoii's memoir, " On 

 Super -acid and Sub -acid Salts," 

 read before the Rnyal Society, Jan. 

 8, 1808 (' Phil. Trans.,' 1808, p. 96, 

 kc), where he even suggests the 



examination of the stability of ag- 

 gregates of particles in different con- 

 figurations, mentioning the tetra- 

 hedron, since become celebrated 

 through Pasteur and Van't Hoff. 



