PHILOSOPHICAL SOCIETY OF WASHINGTON. 169 



has not as yet been satisfactorily made out. The craving of the 

 intellect for unity must therefore pursue its quest beyond and above 

 the material empire of the physical forces. 



The Conception of Natural " Law." — The habitudes of forces 

 form the ultimate goal and boundary of scientific thought : and as 

 the ascertainment and assignment of these habitudes (which we 

 formulate as " laws " of matter) form the object of all science, so 

 are their unerring certainty and uniformity of action at once the 

 necessary postulates and the sole condition of all science. But the 

 formulated " law " is but our mental concept of a habitude and a 

 constancy whose method forever eludes our widest grasp, while for- 

 ever challenging our most daring speculation. What is a law of 

 nature ? What i? there behind it — to ordain or to enforce it. Do 

 forces conform to the canons of an implicit prescription ? Or is 

 the so-called " law " but the summary and explication of autogen- 

 ous deportment? Whichever be our assumption, the marvel and 

 the incomprehensibility alike remain. 



Sir John Herschel, in a playful colloquy " On Atoms," referring 

 to their prompt obedience to the laws of their being, pithily asks : 

 " Do they know them ? Can they remember them ? How else can 

 they obey them ? — conform to a fixed rule ! Then they must be able 

 to apply the rule as the case arises. - - - Their movements, 

 their interchanges, their ' hates and loves,' their ' attractions and re- 

 pulsions/ their ' correlations,' are all determined on the very instant. 

 There is no hesitation, no blundering, no trial and error. A prob- 

 lem of dynamics which would drive Lagrange mad is solved 

 instanter. A differential equation which algebraically written out 

 would belt the earth, is integrated in an eye-twinkle." * 



When we ask ourselves what these inflexible and unfailing laws of 



ment of the subject, "the conservation of electricity; " holding "that 

 electricity, whatever it may prove to be, is not matter and is not energy," 

 and " that it can neither be created nor destroyed." [Nature. May 26, 

 1881: vol. xxiv, p. 78. — Elementary Lessons, [etc.] 12mo. London, 1881.) 

 The electric and caloric fluids furnish a very striking and suggestive 

 parallelism ; and the common rotatory glass cylinder would have furnished 

 Rumford with as pertinent a theme for his argument as his gun-boring 

 lathe. 



* Fortnightly Review. May 15, 1865: pp. 83, 84. Also, Familiar Lec- 

 tures on Scientific Subjects. London, 1866 : pp. 456, 458. 



