620 NOVUM ORGANUM. [BOOK II. 



dered sensible in the rust of metals, and other putrefactions of a 

 like nature, which stop before they arrive at the rudiments of 

 life, which belong to the third species of process. 1 In compact 

 bodies the spirit does not find pores and passages for its escape, 

 and is therefore obliged to force out, and drive before it, th-3 

 tangible parts also, which consequently protrude, whence arises 

 rust and the like. The contraction of the tangible parts, occa 

 sioned by the emission of part of the spirit (whence arises desic 

 cation), is rendered sensible by the increased hardness of the 

 substance, and still more by the fissures, contractions, shrivelling, 

 and folds of the bodies thus produced. For the parts of wood 

 split and contract, skins become shrivelled, and not only that, 

 but, if the spirit be emitted suddenly by the heat of the fire, 

 become so hastily contracted as to twist and roll themselves up. 



On the contrary, when the spirit is retained, and yet expanded 

 and excited by heat or the like (which happens in solid and tena 

 cious bodies), then the bodies are softened, as in hot iron ; 01 

 flow, as in metals ; or melt, as in gums, wax, and the like. The 

 contrary effects of heat, therefore (hardening some substances 

 and melting others), are easily reconciled, y because the spirit is 

 omitted in the former, and agitated and retained in the latter ; 

 the latter action is that of heat and the spirit, the former that 

 of the tangible parts themselves, after the spirit s emission. 



But when the spirit is neither entirely retained nor emitted, 

 but only strives and exercises itself, within its limits, and meets 

 with tangible parts, which obey and readily follow it wherever it 

 leads them, then follows the formation of an organic body, and 

 of limbs, and the other vital actions of vegetables and animals. 

 These are rendered sensible chiefly by diligent observation of the 

 first beginnings, and rudiments or effects of life in animalculae 

 sprung from putrefaction, as in the eggs of ants, worms, mosses, 

 frogs after rain, &c. Both a mild heat and a pliant substance, 

 however, are necessary for the production of life, in order that 

 the spirit may neither hastily escape, nor be restrained by the 

 obstinacy of the parts, so as not to be able to bend and model 

 them like wax. 



Again, the difference of spirit which is important and of effect 

 &quot;n many points (as unconnected spirit, branching spirit, branch 

 ing and cellular spirit, the first of which is that of all inanimate 



* Rust is now well known to be a chemical combination of oxygen 

 with the metal, and the metal when rusty acquires additional weight. 

 His theory as to the generation of animals, is deduced from tha 

 erroneous notion of the possibility of spontaneous generation (a* : t waj 

 termed). See the next paragraph but one. 



7 &quot; Limus ut hie durescit, et haec ut cera liquescit 

 Uuo evd_iu ]Ut: igai.&quot; Virg. Eel. viii. 



