en. ii.] BUYTHM. 301 



typify that which is for ever going on throughout the length 

 and breadth of the Cosmos. Periodicity, rise and fall, re- 

 currence of maxima and minima, — this is the law of all 

 motions whatever, whether exemplified by the star rushing 

 through space, by the leaf that quivers in the breeze, by 

 the stream of blood that courses through the arteries, or 

 by the atom of oxygen that oscillates in harmony with its 

 companion-atom3 of hydrogen in the rain-drop. Always, 

 as in our initial illustration, the forces which are carrying 

 a given portion of matter in a given direction become gradu- 

 ally altered in their distribution, and in their amounts, until 

 the direction of the motion becomes practically reversed; 

 and whether the given portion of matter be a planet or a 

 molecule, the dynamic principle remains the same. Just as 

 Newton's law of inverse squares applies to molecules as well 

 as to masses, so the law of rhythm applies in both cases. 

 Thus what we may call the elementary motions going 

 on throughout the world of phenomena — the elementary 

 motions by the various combinations of which all percep- 

 tible motions are made up — are all rhythmical or oscillatory. 

 The phenomena which are presented to our consciousness 

 as light, heat, electricity, and magnetism, are the products 

 of a perpetual trembling, or swaying to and fro of the 

 invisible atoms of which visible bodies are composed. 

 When we contemplate the heavens on a clear autumn 

 evening, and marvel at the beauty of Sirius, that beauty is 

 conveyed to our senses through the medium of atomic shivers, 

 kept up during the past twenty-two years, at the average 

 rate of six hundred millions of millions per second. The 

 difference between the tropical heat of India and the cold 

 of the Arctic regions is simply the measure of untold millions 

 of tiny differences in the rates of oscillation of countless 

 atoms of atmospheric gases, determined in turn by innumer- 

 able o : dilatory movements propagated from the sun to the 

 earth. The difference between the faradaic current which 



