252 NOVUM OROANUM 



powerful motion. With regard to the first, heat is, on this 

 account, defined as that which separates heterogeneous, and 

 draws together homogeneous substances; a definition of 

 the Peripatetics which is justly ridiculed by Gilbert, who 

 says it is as if one were to define man to be that which 

 sows 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 afterward show, does the same), arising 

 from the desire of the homogeneous parts to unite; the 

 heat then assists them in breaking through that sluggish 

 ness which before restrained their desire. With regard to 

 the assistance derived from the power of a similar 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 the sluggishness 

 of the wood; of which two last experiments we have spoken 

 above in the aphorism on clandestine instances. 84 



The confinement of the motion of lesser congregation, 

 which arises from the power of the predominant body, is 

 shown in the 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 



84 See Aphorism xxv. 



