560 NOVUM ORUANUM. [BOOK II 



examination. As to the honey-dew, resembling manna, which if 

 found in May on the leaves of the oak, we are of opinion that it 

 is not condensed by any harmony or peculiarity of the oak leaf, 

 but that whilst 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. b 



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, notwithstanding 

 the boasting of quacks. For the effects of intense heat are 

 examined and observed, whilst those of a more gentle degree of 

 heat, being of the most frequent occurrence in the paths of 

 nature, are, on that very account, least known. We see, there 

 fore, the furnaces, which are most esteemed, employed in in 

 creasing the spirits of bodies to a great extent, as in the strong 

 acids, and some chymical oils ; whilst the tangible parts are 

 hardened, and, when the volatile part has escaped, become some 

 times fixed ; the homogeneous parts are separated, and the hete 

 rogeneous 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 imitation of the effect of the 

 Bun, 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 imitated in species, perfected in power, and varied 

 in quantity ; to which should be added the acceleration in point 

 of time. Kust, for instance, is the result of a long process, but 

 crocus martis is obtained immediately ; and the same may be 

 observed of natural verdigris and ceruse. Crystal is formed 

 slowly, whilst glass is blown immediately : stones increase 

 slowly, whilst bricks arc baked immediately, &c. In the mean 

 time (with regard to our present subject) every different species 

 of heat should, with its peculiar effects, be diligently collected 

 and inquired into; that of the heavenly bodies, whether their 

 rays be direct, reflected, or refracted, or condensed by a burning- 

 glass ; that of lightning, flame, and ignited charcoal ; that of fire 

 of different materials, either open or confined, straitened or 

 overflowing, qualified by the different forms of the furnaces, 

 excited by the bellows, or quiescent, removed to a greater or lesi 



fc Jt may often be observed on the leaves of the lime and other tree* 



