OF NATURAL PHILOSOPHY. 173 



cannot conceive the atoms of a grain of sand to be 

 as remote from each other (proportionally to their 

 sizes) as the stars of the firmament; and why 

 there may not be going on, in that little microcosm, 

 processes as complicated and wonderful as those of 

 the great world around us. Yet the student who 

 makes any progress in natural philosophy will en- 

 counter numberless cases in which this transfer ^of 

 ideas from the one extreme of magnitude to the 

 other will be called for : he will find, for instance, 

 the phenomena of the propagation of winds referred 

 to the same laws which regulate the propagation 

 of motions through the smallest masses of air ; those 

 of lightning assimilated to the mere communication 

 of an electric spark, and those of earthquakes to the 

 tremors of a stretched wire : in short, he must lay 

 his account to finding the distinction of great and 

 little altogether annihilated in nature : and it is well 

 for man that such is the case, and that the same 

 laws, which he can discover and verify in his own 

 circumscribed sphere of power, should prove avail- 

 able to him when he comes to apply them on the 

 greatest scale; since it is thus only that he is en- 

 abled to become an exciting cause in operations of 

 any considerable magnitude, and to vindicate his 

 importance in creation. 



(183.) But the business of induction does not 

 end here : its final result must be followed out into 

 all its consequences, and applied to all those cases 

 which seem even remotely to bear upon the sub- 

 ject of enquiry. Every new addition to our stock 

 of causes becomes a means of fresh attack with new 

 vantage ground upon all those unexplained parts of 



