)ETECTION OF DIFFERENT KINDS OF STATIC CONDITIONS. 443 



ng out intermediate ideas that showed the agreement or 

 lisagreement of the ideas as expressed in the proposition 

 le demonstrated,' was 'led into the truth and certainty of 

 phose propositions.' A real static condition is discovered 

 by the same methods as those employed in the discovery of 

 pauses ; an apparent one is detected by its non-agreement 

 vvith one or more varied instances of a phenomenon ; a 

 releasing or exciting condition may be distinguished from 

 ii cause by its non-proportionality to the effect, whilst it 

 is at the same time an inseparable and indispensable con- 

 comitant ; a guiding one may be known by its change for 

 another being attended by a change either in the kind or 

 degree of the effect. 



The discovery of guiding conditions is often more diffi- 

 jcult than that of causes, because in a multitude of cases it 

 consists of a hidden static molecular arrangement, whilst a 

 bause may be a visible mechanical motion ; it is also fre- 

 quently of greater importance, because a knowledge of 

 guiding conditions would in many cases enable us to place 

 'physical and chemical phenomena upon a geometrical 

 jmolecular basis. At present we know but little of the 

 statical molecular conditions of physical or chemical 

 actions, or of what is termed the < internal resistance ' of 

 substances, which so largely determines the kind and 

 degree of effect of the physical and chemical forces in 

 different cases. Before we can essentially (not to say 

 I completely) explain a dynamic phenomenon, we require to 

 discover not only the true cause but also the true guiding 

 ! conditions which determine in what manner and to what 

 extent that cause operates. 



A limiting or an obstructive condition may be found 



| by the variation of its degree being attended by a varia- 



! tion of that of the effect within certain limits, whilst the 



amount of the cause remains constant ; and a preventive 



