BOOK II.] INSTANCES OP PREDOMINANCE 653" 



Tvill raise a given weight, and so far the motion of liberty pre- 

 dominates over that of the greater congregation, but if the 

 weight be greater, the former motion yields. A piece of leather 

 stretched to a certain point does not break, and so far the 

 motion of continuity predominates over that of tension, but if 

 the tension be greater, the leather breaks, and the motion of 

 continuity yields. A certain quantity of water flows through a 

 chink, and so far the motion of greater congregation pro- 

 dominates over that of continuity, but if the chink bo 

 smaller it yields. If a musket be charged with ball and 

 powdered sulphur alone, and lire be applied, the ball is not dis- 

 charged, in which case the motion of greater congregation over- 

 comes that of matter ; but when gunpowder is used, the motion 

 of matter in the sulphur predominates, being assisted by that 

 motion, and the motion of avoidance in the nitre ; and so of the 

 rest. For wrestling instances (which show the predominance of 

 powers, and in what manner and proportion they predominate and 

 yield) must be searched for with active and industrious diligence. 



The methods and nature of this yielding must also be dili- 

 gently examined, as for instance, whether the motions completely 

 cease, or exert themselves, but are constrained. For in the 

 bodies with which we are acquainted, there is no real but an 

 apparent rest, either in the whole or in parts. This apparent 

 rest is occasioned either by equilibrium, or the absolute pre- 

 dominance of motions. By equilibrium, as in the scales of the 

 balance, which rest if the weights be equal. By predominance, as 

 in perforated jars, in which the water rests, and is prevented from 

 falling by the predominance of the motion of connection. It is, 

 however, to be observed (as we have said before), how far the 

 yielding motions exert themselves. For if a man be held 

 stretched out on the ground against his will, with arms and legs 

 bound down, or otherwise confined, and yet strive with all his 

 power to get up, the struggle is not the less, although ineffectual. 

 The real state of the case (namely, whether the yielding motion 

 be, as it were, annihilated by the predominance, or there be 

 rather a continued, although an invisible effort) will, perhaps, 

 appear in the concurrence of motions, although it escape our 

 notice in their conflict. For instance ; let an experiment be 

 made with muskets ; whether a musket-ball, at its utmost range 

 in a straight line, or (as it is commonly called) point blank, strike 

 with less force when projected upwards, where the motion of the 

 blow is simple, than when projected downwards, where the 

 motion of gravity concurs with the blow. 



The rules of such instances of predominance as occur should 

 be collected : such as the following ; the more general the 

 desired advantage is, the stronger will be the motion ; tho 

 motion of connection, for instance, which relates to the inter- 

 oourse of the parts pf the universe, w more powerful than that 



