NOVUM ORGANUM 447 



nant and contrary nature, whilst in this of which we treat (if 

 there be no impediment or restraint), the parts are united by 

 their affinity, although there be no foreign nature to create a 

 struggle; 2dly, because the union is closer and more select. 

 For in the other motion, bodies which have no great affinity 

 unite, if they can but avoid the hostile body, whilst in this, sub- 

 stances which are connected by a decided kindred resemblance 

 come together and are moulded into one. It is a motion existing 

 in all compound bodies, and would be readily seen in each, if it 

 were not confined and checked by the other affections and ne- 

 cessities of bodies which disturb the union. 



This motion is usually confined in the three following man- 

 ners : by the torpor of the bodies ; by the power of the pre- 

 dominating body; by external motion. With regard to the 

 first, it is certain that there is more or less sluggishness in 

 tangible bodies, and an abhorrence of locomotion ; so that un- 

 less excited they prefer remaining contented with their actual 

 state, to placing themselves in a better position. There are 

 three means of breaking through this sluggishness heat ; the 

 active power of a similar body ; vivid and powerful motion. 

 With regard to the first, heat is, on this account, defined as that 

 which separates heterogeneous, and draws together homogene- 

 ous 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 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 similar body, it is most conspicu- 

 ous 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 in- 

 stances.* 



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 



