56 ULTIMATE SCIENTIFIC IDEAS. 



divisible units, is symbolic and incapable of being complete- 

 ly thought out, it may yet be supposed to find indirect veri- 

 fication in the truths of chemistry. These, it is argued, 

 necessitate the belief that Matter consists of particles of spe- 

 cific weights, and therefore of specific sizes. The general 

 law of definite proportions seems impossible on any other 

 condition than the existence of ultimate atoms ; and though 

 the combining weights .of the respective elements are termed 

 by chemists their " equivalents/' for the purpose of avoid- 

 ing a questionable assumption, we are unable to think of 

 the combination of such definite weights, without supposing 

 it to take place between definite numbers of definite parti- 

 cles. And thus it would appear that the Newtonian view is 

 at any rate preferable to that of Boscovich. A dis- 



ciple of Boscovich, however, may reply that his master's 

 theory is involved in that of Newton ; and cannot indeed be 

 escaped. " What," he may ask, " is it that holds together 

 the parts of these ultimate atoms? " "A cohesive force," 

 his opponent must answer. " And what," he may continue, 

 "is it that holds together the parts of any fragments into 

 which, by sufficient force, an ultimate atom might be 

 broken? " Again the answer must be a cohesive force. 

 " And what," he may still ask, " if the ultimate atom were, 

 as we can imagine it to be, reduced to parts as small in pro- 

 portion to it, as it is in proportion to a tangible mass of 

 matter what must give each part the ability to sustain it- 

 self, and to occupy space? " Still there is no answer but a 

 cohesive force. Carry the process in thought as far as we 

 may, until the extension of the parts is less than can be im- 

 agined, we still cannot escape the admission of forces by 

 which the extension is upheld; and we can find no limit 

 until we arrive at the conception of centres of force without 

 any extension. 



Matter then, in its ultimate nature, is as absolutely in- 

 comprehensible as Space and Time. Frame what suppo- 

 sitions we may, we find on tracing out their implications 



