NOVUM OROANUM 279 



arity of the oak leaf, but that while it falls equally upon 

 other leaves it is retained and continues on those of the 

 oak, because their texture is closer, and not so porous as 

 that of most of the other leaves. 94 



With regard to heat, man possesses abundant means and 

 power; but his observation and inquiry are defective in 

 some respects, and those of the greatest importance, not 

 withstanding the boasting of quacks. For the effects of 

 intense heat are examined and observed, while those of a 

 more gentle degree of heat, being of the most frequent oc 

 currence in the paths of nature, are, on that very account, 

 least known. We see, therefore, the furnaces, which are 

 most esteemed, employed in increasing the spirits of bodies 

 to a great extent, as in the strong acids, and some chemical 

 oils; while the tangible parts are hardened, and, when the 

 volatile part has escaped, become sometimes fixed; the 

 homogeneous parts are separated, and the heterogeneous 

 incorporated and agglomerated in a coarse lump; and (what 

 is chiefly worthy of remark) the junction of compound 

 bodies, and the more delicate conformations are destroyed 

 and confounded. But the operation of a less violent heat 

 should be tried and investigated, by which more delicate 

 mixtures and regular conformations may be produced and 

 elicited, according to the example of nature, and in imita 

 tion of the effect of the sun, which we have alluded to in 

 the aphorism on the instances of alliance. For the works 

 of nature are carried on in much smaller portions, and in 

 more delicate and varied positions than those of fire, as we 

 now employ it. But man will then appear to have really 

 augmented his power, when the works of nature can be 



It may often be observed on the leaves of the lime and other trees. 



