442 ACTUAL WORKING IN ORIGINAL RESEARCH. 



exercise of the individual force in the particular manner, 

 as a non-conductor of electricity prevents an electric cur- 

 rent, or as absence of contact prevents chemical action ; 

 such a condition may also consist of an equivalent oppos- 

 ing cause. That which is an obstructive or preventive 

 condition of one effect must of necessity be an aiding or 

 permitting one of an effect of a contrary kind. 



To produce a given dynamic physical or chemical 

 effect, there is required 1st, a source of physical or che- 

 mical power ; 2nd, a releasing or exciting condition of the 

 force ; 3rd, a determining or guiding condition to direct 

 the power ; 4th, a limiting or regulating condition to de- 

 termine and regulate the amount of effect ; and 5th, the 

 absence of obstructive and of all preventive conditions. 

 The limiting condition is usually either the amount of 

 available force or the limit of action of the preventive or 

 obstructive conditions. 



Under every change of condition new effects ensue, 

 even though we do not perceive them ; substances re- 

 arrange their atoms or molecules, and either expand, and 

 if compound are decomposed and separated into their 

 constituents, or a converse change occurs the substances 

 contract, simple ones unite to form compounds, and com- 

 pounds differentiate into complex structures ; also, either 

 several forces concur in their action and are converted into 

 one, or one force in the latent state is set free and con- 

 verted into several others. 



Static conditions being often of a more fundamental and 

 obscure character, are also often more difficult to discover 

 than dynamic causes. The discovery of a general static 

 relation between two forms of energy is very important : 

 6 When we find out an idea, by the intervention of which 

 we discover the connection of two others, this is a revela- 

 tion of God to us by the voice of reason.' ' Newton, find- 



