BOOK II.] MOTION OP CONGREGATION. 543 



Bowg wheat and plants vineyards ; being only a definition 

 deduced from effects, and those but partial. But it is still more 

 to be blamed, because those effects, such as they are, are not a 

 peculiar property of heat, but a mere accident (for cold, as we 

 shall afterwards show, does the same), arising from the desire of 

 the homogeneous parts to unite ; the heat then assists them in 

 breaking through that sluggishness which before restrained their 

 desire. With regard to the assistance derived from the power 

 of a simil-ar body, it is most conspicuous in the magnet when 

 armed with steel, for it excites in the steel a power of adhering 

 to steel, as a homogeneous substance, the power of the magnet 

 breaking through the sluggishness of the steel. With regard to 

 the assistance of motion, it is seen in wooden arrows or points, 

 which penetrate more deeply into wood than if they were tipped 

 with iron, from the similarity of the substance, the swiftness of 

 the motion breaking through tho sluggishness of the wood ; of 

 which two last experiments we have spoken above in the aphorism 

 on clandestine instances. p 



The confinement of the motion of lesser congregation, which 

 arises from the power of the predominant body, is shown in tho 

 decomposition of blood and urine by cold. For as long as these 

 substances are filled with the active spirit, which regulates and 

 restrains each of their component parts, as the predominant 

 ruler of the whole, the several different parts do not collect 

 themselves separately on account of the check ; but as soon as 

 that spirit has evaporated, or has been choked by the cold, then 

 the decomposed parts unite, according to their natural desire. 

 Hence it happens, that all bodies which contain a sharp spirit (as 

 salts and the like), last without decomposition, owing to the per 

 manent and durable power of the predominating and imperious 

 spirit. 



The confinement of the motion of lesser congregation, which 

 arises from external motion, is very evident in that agitation of 

 bodies which preserves them from putrefaction. For all putre 

 faction depends on the congregation of the homogeneous parts, 

 whence, by degrees, there ensues a corruption of the first form 

 (as it is called), and the generation of another. For the decom 

 position of the original form, which is itself the union of the 

 homogeneous parts, precedes the putrefaction, which prepares 

 the way for the generation of another. This decomposition, if 

 not interrupted, is simple ; but if there be various obstacles, 



gitrefactious ensue, which are the rudiments of a new generation, 

 ub if (to come to our present point) a frequent agitation be 

 excited by external motion, the motion towards union (which is 

 delicate and gentle, and requires to be free from all external 



p See Aphorism xxv. 



