THE BELFAST ADDRESS. 161 



between Gassendi and Maxwell. The one postulates, 

 the other infers his first cause. In his ' manufac- 

 tured articles/ as he calls the atoms, Professor Max- 

 well finds the basis of an induction, which enables him 

 to scale philosophic heights considered inaccessible 

 by Kant, and to take the logical step from the atoms 

 to their Maker. 



Accepting here the leadership of Kant, I doubt the 

 legitimacy of Maxwell's logic; but it is impossible not 

 to feel the ethic glow with which his lecture concludes. 

 There is, moreover, a very noble strain of eloquence 

 in his description of the steadfastness of the atoms: 

 ' Natural causes, as we know, are at work, which tend 

 to modify, if they do not at length destroy, all the 

 arrangements and dimensions of the earth and the 

 whole solar system. But though in the course of ages 

 catastrophes have occurred and may yet occur in the 

 heavens, though ancient systems may be dissolved and 

 new systems evolved out of their ruins, the molecules 

 out of which these systems are built the foundation 

 stones of the material universe remain unbroken and 

 unworn.' 



The atomic doctrine, in whole or in part, was enter- 

 tained by Bacon, Descartes, Hobbes, Locke, Newton, 

 Boyle, and their successors, until the chemical law of 

 multiple proportions enabled Dalton to confer upon it 

 an entirely new significance. In our day there are 

 secessions from the theory, but it still stands firm. 

 Loschmidt, Stoney, and Sir William Thomson have 

 sought to determine the sizes of the atoms, or rather to 

 fix the limits between which their sizes lie; while the 

 discourses of Williamson and Maxwell delivered in 

 Bradford in 1873 illustrate the present hold of the 

 doctrine upon the foremost scientific minds. In fact, 

 it may be doubted whether, wanting this fundamental 



