NOVUM ORGANUM. 289 



sericum, in mollitie ; vermiculi cutis, in quantitate animalium ; 

 et caetera. 



XXXV. 



Inter Praerogativas Instantiarum, ponemus loco decimo tertio 

 Instantias Fcederis sive Unionis. Eae sunt, quae confundunt et 

 adunant naturas quae existimantur esse heterogeneae, et pro 

 talibus notantur et signantur per divisiones receptas. 



At Instantiae Foederis ostendunt operationes et efFectus quae 

 deputantur alicui ex illis heterogeneis ut propria, competere 

 etiam aliis ex heterogeneis ; ut convincatur ista heterogenia 

 (quae in opinione est) vera non esse aut essentialis, sed nil aliud 

 esse quam modificatio naturae communis. Optimi itaque sunt 

 usus ad elevandum et evehendum intellectum a differentiis ad 

 genera; et ad tollendum larvas et simulachra rerum, prout 

 occurrunt et prodeunt personatae in substantiis concretis. 



Exempli gratia : sit natura inquisita Calidum. Omnino 

 videtur esse divisio solennis et authentica quod sint tria genera 

 caloris; viz. calor crelestium, calor animalium, et calor ignis; 

 quodque isti calores (prassertim unus ex illis comparatus ad 

 reliquos duos) sint ipsa essentia et specie, sive natura specifica, 

 differentes et plane heterogenei ; quandoquidem calor coelestium 

 et animalium generet et foveat, at calor ignis contra corrumpat 

 et destruat. Est itaque Instantia Fo3deris experimentum illud 

 satis vulgatum, cum recipitur ramus aliquis vitis intra domum 

 ubi sit focus assiduus, ex quo maturescunt uvae etiam mense 

 integro citius quam foras ; ita ut maturatio fructus etiam pen- 

 dentis super arborem fieri possit scilicet ab igne, cum hoc 

 ipsum videatur esse opus proprium solis. 1 Itaque ab hoc initio 



eighteenth century. Bacon's want of acquaintance with it, implied in this and other 

 passages, is therefore not surprising. 



1 The regular use of artificial heat in green-houses and conservatories was not 

 known in Bacon's time. In the Maison Champetre, an encyclopaedia of gardening 

 and agriculture published in 1607, nothing is said of it; nor is there anything on the 

 subject in the writings of Porta, though in his Nat. Mag. he has spoken of various 

 modes of accelerating the growth of fruits and flowers. In the Sylva Sylvarum(4l2.), 

 however, Bacon speaks of housing hot-country plants to save them, and, in the Essay 

 on Gardens, of stoving myrtles. The idea of what are now called green-houses was 

 introduced into England from Holland about the time of the Revolution. The 

 orangery at Heidelberg, formed, I believe, about the middle of the seventeenth century, 

 is said to be the earliest conservatory on record. 



It is related that Albertus Magnus, entertaining the emperor at Cologne during the 

 winter, selected for the place of entertainment the garden of his monastery. Every- 

 thing was covered with snow, and the guests were much inclined to be discontented ; 

 but when the feast began, the snow cleared away ; the trees put forth, first leaves, 

 then blossoms, then fruit; and the climate became that of summer. This glorious 

 summer, which had thus abruptly succeeded to the winter of their discontent, lasted 



VOL. I. U 



