LIFE AND ORGANISATION. 99 



believe all muscular action perhaps every vital action 

 to be attended with some chemical change in the parts 

 concerned; and every chemical change, as we know, pro- 

 duces disturbance of the electrical equilibrium. Changes of 

 temperature moreover, or molecular motions, each belonging 

 to muscular contraction, may be concerned in evolving these 

 electrical currents. But whatever the ambiguities of the 

 question, it is obvious that they all lie within that single 

 circle which comprehends and connects the great Co-related 

 Physical Forces of the universe ; a magical circle we may 

 well call it, as comprising within itself some of the most 

 profound and mysterious problems which human reason can 

 venture to approach. 



We must here come to a close ; although there are still 

 numerous topics we might bring under consideration, illustra- 

 ting the efforts and results of modern science in relation to 

 this great subject of Life on the earth. It will have been 

 noticed how often the question of Final Causes comes before 

 us, as a consequence, and even integral part, of these en- 

 quiries. We have already alluded to this point ; but cannot 

 conclude without reverting once again to a principle of 

 reasoning which it is of signal importance should be rightly 

 appreciated in the interpretations it affords. A misplaced 

 sophistry, fortifying itself by a single phrase of Lord Bacon's 

 of doubtful meaning, has sought to impugn this method and 

 the conclusions thence derived. It cannot be done. Such 

 reasoning is an integral necessity of our mental constitution. 

 The fallacy lies here, as so often elsewhere, in imputing to the 

 use of the faculty what belongs to its abuse ; since, if using 

 that caution which the nature of the subject inculcates, we 

 may safely and profitably employ it as a guide in research, 

 as well as an exponent of discovery, in every part of the 

 great domain of created life. 



H 2 



