BOOK !L] INSTANCES OP ALLIANCE. 503 



brain, and excites them to .action, as the fire would operate on 

 water or air, and in the result produces life. Eggs arc sometimes 

 hatched by the heat of fire, an exact imitation of animal heat ; 

 and there arc many instances of the like nature, so that no one 

 can doubt that the heat of fire, in many cases, can be modified 

 till it resemble that of the heavenly bodies and of animals. 



Again, let the required natures be motion and rest. There 

 appears to be a settled classification, grounded on the deepest 

 philosophy, that natural bodies either revolve, move in a straight 

 line, or stand still and rest. For there is either motion without 

 limit, or continuance within a certain limit, or a translation to 

 wards a certain limit. The eternal motion of revolution appears 

 peculiar to the heavenly bodies, rest to this our globe, and the 

 other bodies (heavy and light, as they arc termed, that is to say, 

 placed out of their natural position) arc borne in a straight line 

 to masses or aggregates which resemble them, the light towards 

 the heaven, the heavy towards the earth ; aud all this is very 

 fine language. 



But we have an instance of alliance in low comets, which 

 revolve, though far below the heavens; and the fiction of Aristotle, 

 of the comet being fixed to, or necessarily following some star, 

 lias been long since exploded; not only because it is improbable 

 in itself, but from the evident fact of the discursive and irregular 

 motion of comets through various parts of the heavens. 



Another instance of alliance is that of the motion of air, 

 which appears to revolve from east to west within the tropics, 

 where the circles of revolution are the greatest. 



The flow and ebb of the sea would perhaps be another instance, 

 if the water were once found to have a motion of revolution, 

 though slow and hardly perceptible, from east to west, subject, 

 however, to a reaction twice a day. If this be so, it is clear that 

 the motion of revolution is not confined to the celestial bodies, 

 but is shared, also, by air and water. 



^gain, the supposed peculiar disposition of light bodies to rise 

 is rather shaken; and here we may find an instance of alliance in 

 a water bubble. For if air be placed under water, it rises rapidly 

 towards the surface by that striking motion (as Democritus terms 

 it) with which the descending water strikes the air and raises it, 

 not by any struggle or effort of the air itself; and when it has 

 reached tlio surface of the water, it is prevented from ascending 



1 Seneca was a sounder astronomer than Bacon. lie ridiculed the 

 Mea of the motion of any heavenly bodies being irregular, and predicted 

 that the day would come, when the laws which guided the revolution 

 oi these bodies would be proved to be identical with those which con 

 trolled the motions of th? planets. The anticipation watt real iz.- 1 b) 



