NOVUM ORGANUM 443 



tive strength, and thence a demonstration and definition of the 

 instances in question, may be rendered more clear. 



Let the first motion be that of the resistance of matter, which 

 exists in every particle, and completely prevents its annihila- 

 tion ; so that no conflagration, weight, pressure, violence, or 

 length of time can reduce even the smallest portion of matter 

 to nothing, or prevent it from being something, and occupying 

 some space, and delivering itself (whatever straits it be put to), 

 by changing its form or place, or, if that be impossible, remaining 

 as it is; nor can it ever happen that it should either be nothing 

 or nowhere. This motion is designated by the schools (which 

 generally name and define everything by its effects and incon- 

 veniences 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 useless 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 sepa- 

 rated 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 per- 

 forated 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 liberty, 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 by the 

 other piece of root or pellet, or by the ramrod. We have ex- 

 amples of their escape from tension, in the motion of the air 

 that remains in glass eggs after suction, in strings, leather, and 

 cloth, which recoil after tension, unless it be long continued. 

 The schools define this by the term of motion from the form 

 of the element ; injudiciously enough, since this motion is to be 

 found not only in air, water, or fire, but in every species of 

 solid, as wood, iron, lead, cloth, parchment, etc., each of which 



