MULTIPLICATION OF EFFECTS. 33 



the decomposition of one force into many forces does not 

 end here : each of the several changes produced becomes 

 the parent of further changes. The carbonic acid given 

 off will by and by combine with some base; or under the 

 influence of sunshine give up its cai'bon to the leaf of a 

 plant. The water will modify the hygrometric state of the 

 air around ; or, if the current of hot gases containing it 

 come against a cold body, will be condensed : altering the 

 temperature, and perhaps the chemical state, of the surface 

 it covers. The heat given out melts the subjacent tallow, 

 and expands whatever it warms. The light, falUng on vari- 

 ous substances, calls forth from them reactions by which 

 it is modified ; and so divers colours are produced. Similarly 

 even with these secondary actions, which may be traced out 

 into ever-multiplying ramifications, until they become too 

 minute to be appreciated. And thus it is with all changes 

 whatever. No case can be named in which an active force 

 does not evolve forces of several kinds, and each of these, 

 other groups of forces. Universally the effect is more com- 

 plex than the cause. 



Doubtless the reader already foresees the course of our 

 argument. This multiplication of results, which is displayed 

 in every event of to-day, has been going on from the begin- 

 ning ; and is true of the grandest phenomena of the uni- 

 verse as of the most insignificant. From the law that every 

 active force produces more than one change, it is an inevit- 

 able corollary that through all time there has been an ever- 

 growing complication of things. Starting with the ultimate 

 fact that every cause produces more than one effect, we may 

 readily see that throughout creation there must have gone 

 on, and must still go on, a never-ceasing transformation of 

 the homogeneous into the heterogeneous. But let us trace 

 Dut this truth in detail.^' 



* A correlative truth which ought also to be taken into account (that 

 the state of homogeneity is one of unstable equilibrium), but which it 

 2* 



