NOVUM ORGANUM. 131 



and hidden and weak in the iron. It is to be observed also 

 that small wooden arrows without an iron point, when dis 

 charged from large mortars, penetrate further into wooden 

 substances (such as the ribs of ships or the like), than the 

 same arrows pointed with iron ;* owing to the similarity of 

 substance, though this quality was previously latent in the 

 wood. Again, although in the mass, air does not appear to 

 attract air, nor water water; yet when one bubble is brought 

 near another, they are both more readily dissolved from the 

 tendency to contact of the water with the water, and the 

 air with the air.f These clandestine instances (which are, 

 as has been observed, of the most important service) are 

 principally to be observed in small portions of bodies, for 

 the larger masses observe more universal and general forms, 

 as will be mentioned in its proper place. 



26. In the fifth rank of prerogative instances we will 

 class Constitutive instances, which we are wont also to call 

 collective instances. They constitute a species or lesser 

 form, as it were, of the required nature. For since the real 

 forms (which are always convertible with the given nature) 

 lie at some depth, and are not easily discovered, the neces 

 sity of the case and the infirmity of the human understand 

 ing require that the particular forms, which collect certain 

 groups of instances (but by no means all) into some common 

 notion, should not be neglected, but most diligently ob 

 served. For whatever unites nature, even imperfectly, opens 

 the way to the discovery of the form. The instances, there 

 fore, which are serviceable in this respect are of no mean 

 power, but endowed with some degree of prerogative. 



Here, nevertheless, great care must be taken, that after 

 the discovery of several of these particular forms, and the 

 establishing of certain partitions or divisions of the required 

 nature derived from them, the human understanding do not 

 at once rest satisfied, without preparing for the investiga 

 tion of the great or leading form, and, taking it for ganted 

 that nature is compound and divided from its very root, 



* Query? 



t The real cause of this phenomenon is the attraction of the surface water in 

 the vessel by the sides of the bubbles. When the bubbles approach, the sides 

 nearest each other both tend to raise the small space of water between them, and 

 consequently less water is raised by each of these nearer sides, than by the ex 

 terior part of the bubble, and the greater weight of the water raised on the exterior 

 parts pushes the bubbles together. In the same manner a bubble near the side 

 of a vessel is pushed towards it ; the vessel and bubble both drawing the water 

 that is between them. The latter phenomenon cannot be explained on Bacon s 

 hypothesis. 



