176 CORRELATION OF PHYSICAL FORCES. 



no external work, but is effort alone, than when that effort 

 and contraction are employed dynamically, so as to raise a 

 weight or produce mechanical work. 



Thus, though we may see no present promise of being 

 able to resolve sensations into their ultimate elements, or to 

 trace, physically, the link which unites volition with exertion 

 or effort, in terms of our own consciousness of it, we may 

 hope to approximate the solution of these deeply interesting 

 questions. 



In the same individual the chemical and physical state of 

 the secretions in the warm may be compared with those in 

 the cold parts of the body. The changes in digestion and 

 respiration, when the body is in a state of rest, may be com- 

 pared with those which obtain when it is in a state of activity. 

 The relations with external matter, maintaining, by the con- 

 stant play of natural forces, the vital nucleus, or the organi- 

 sation by means of which matter and force receive, for a 

 definite period, a definite incorporation and direction, may be 

 ascertained, while the more minute structural changes are 

 revealed to us by the ever-improving powers of the micro- 

 scope ; and thus step by step we may learn that which it is 

 given to us to learn, boundless in its range and infinite in its 

 progress, and therefore never giving a response to the ultimate 

 Why? 



As the first glimpse of a new star is caught by the eye of 

 the astronomer while directing his vision to a different point 

 of space, and disappears when steadfastly gazed at, only to 

 have its position and figure ultimately ascertained by the em- 

 ployment of more penetrative powers, so the first scintillations 

 of new natural phenomena frequently present themselves to 

 the eye of the observer, dimly seen when viewed askance, 

 and disappearing if directly looked for. When new powers 

 of thought and experiment have developed and corrected the 

 first notions, and given a character to the new image, proba- 

 bly very different from the first impression, fresh objects are 



