Mr. W. J. aiACQUORN Rai^kine uh the Science of Energetics. 399 



upon it ; then, if the increase of actual energy so produced be imme- 

 diately diffused amongst other parts, so as to restore the uniformity of 

 the metabatic function, the whole process will be irreversible. This spe- 

 culation, however, is, for the present, partly hypothetical ; and, therefore 

 does not, strictly speaking, form part of the science of energetics. 



XIX. Measuhement of Time. 



The general relations between energy and time must form an important 

 branch of the science of energetics ; but for the present, all that I am 

 prepared to state on this subject is the following definition of equal 



TIMES : — 



Equal times are the times in which equal quantities of the same kind of 

 work are performed by equal and similar substances, under wholly similar 

 circumstances. 



XX. Concluding Remarks. 



It is to be observed, that the preceding articles are not the results of a 

 new and hitherto untried speculation, but are the generalized expression 

 of a method of reasoning which has already been applied with success to 

 special branches of physics. 



In this brief essay, it has not been attempted to do more than to give 

 an outline of some of the more obvious principles of the science of 

 energetics, or the abstract theory of physical phenomena in general ; a 

 science to which the maxim, true of all science, is specially applicable — 

 that its subjects are boundless, and that they never can, by human labours, 

 be exhausted, nor the science brought to perfection. 



