172 FRAGMENTS OF SCIENCE 



Eternal, produce by their subsequent interaction all the 

 phenomena of the material world. There seems to be this 

 difference, however, between Gassendi and Maxwell. The 

 one postulates, the other infers his first cause. In his 

 "manufactured articles;" as he calls the atoms, Professor 

 Maxwell 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: "Natu- 

 ral 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 deter- 

 mine the sizes of the atoms, or rather to fix the limits 

 between which their sizes lie; while the discourses of Wil- 



