NOVUM ORGANUM 245 



This motion is designated by the schools (which generally 

 name and define everything by its effects and inconven 

 iences rather than by its inherent cause) by the axiom, that 

 two bodies cannot exist in the same place, or they call it a 

 motion to prevent the penetration of dimensions. It is use 

 less to give examples of this motion, since it exists in 

 every body. 



Let the second motion be that which we term the motion 

 of connection, by which bodies do not allow themselves to 

 be separated at any point from the contact of another body, 

 delighting, as it were, in the mutual connection and contact. 

 This is called by the schools a motion to prevent a vacuum. 

 It takes place when water is drawn up by suction or a 

 syringe, the flesh by cupping, or when the water remains 

 without escaping from perforated jars, unless the mouth be 

 opened to admit the air, and innumerable instances of a like 

 nature. 



Let the third be that which we term the motion of lib 

 erty, by which bodies strive to deliver themselves from any 

 unnatural pressure or tension, and to restore themselves to 

 the dimensions suited to their mass; and of which, also, 

 there are innumerable examples. Thus, we have examples 

 of their escaping from pressure, in the water in swimming, 

 in the air in flying, in the water again in rowing, and in the 

 air in the undulation of the winds, and in springs of 

 watches. An exact instance of the motion of compressed 

 air is seen in children s popguns, which they make by 

 scooping out elder-branches or some such matter, and 

 forcing in a piece of some pulpy root or the like, at each 

 end ; then they force the root or other pellet with a ramrod 

 to the opposite end, from which the lower pellet is emitted 

 and projected with a report, and that before it is touched 



