4S4 BACON 



medium. For one medium is adapted to light, another to 

 sound, another to heat and cold, another to magnetic action, 

 and so on with regard to the other actions. 



Let the sixteenth be that which we term the royal or political 

 motion, by which the predominant and governing parts of any 

 body check, subdue, reduce, and regulate the others, and force 

 them to unite, separate, stand still, move, or assume a certain 

 position, not from any inclination of their own, but according to 

 a certain order, and as best suits the convenience of the govern- 

 ing part, so that there is a sort of dominion and civil govern- 

 ment exercised by the ruling part over its subjects. The motion 

 is very conspicuous in the spirits of animals, where, as long as 

 it is in force, it tempers all the motions of the other parts. It is 

 found in a less degree in other bodies, as we have observed in 

 blood and urine, which are not decomposed until the spirit, 

 which mixed and retained their parts, has been emitted or ex- 

 tinguished. Nor is this motion peculiar to spirits only, al- 

 though in most bodies the spirit predominates, owing to its 

 rapid motion and penetration ; for the grosser parts predomi- 

 nate in denser bodies, which are not filled with a quick and ac- 

 tive spirit (such as exists in quicksilver or vitriol), so that unless 

 this check or yoke be thrown off by some contrivance, there is 

 no hope of any transformation of such bodies. And let not any- 

 one suppose that we have forgotten our subject, because we 

 speak of predominance in this classification of motions, which 

 is made entirely with the view of assisting the investigation of 

 wrestling instances, or instances of predominance. For we do 

 not now treat of the general predominance of motions or powers, 

 but of that of parts in whole bodies, which constitutes the par- 

 ticular species here considered. 



Let the seventeenth motion be the spontaneous motion of 

 revolution, by which bodies having a tendency to move, and 

 placed in a favorable situation, enjoy their peculiar nature, pur- 

 suing themselves and nothing else, and seeking, as it were, to 

 embrace themselves. For bodies seem either to move without 

 any limit, or to tend towards a limit, arrived at which they either 

 revolve according to their peculiar nature, or rest. Those 

 which are favorably situated, and have a tendency to motion, 

 move in a circle with an eternal and unlimited motion; those 

 which are favorably situated and abhor motion, rest. Those 

 which are not favorably situated move in a straight line (as their 

 shortest path), in order to unite with others of a congenial nat- 

 ure. This motion of revolution admits of nine differences : I. 

 with regard to the centre about which the bodies move; 2. 

 the poles round which they move; 3. the circumference or 

 orbit relatively to its distance from the centre ; 4. the velocity 

 or greater or less speed with which they revolve ; 5. the direc- 



