FRANCIS BACON ii 



the apothecaries, who, when they cannot obtain any simple ingredient, 

 take a succedaneum, or quid pro quo, as they term it, such as aloes for 

 xylobalsamum, cassia for cinnamon. In the same manner we should 

 look diligently about us, to ascertain whether there may be any sub- 

 stitutes for cold, that is to say, in what other manner condensation 

 can be effected, which is the peculiar operation of cold. Such con- 

 densations appear hitherto to be of four kinds only. i. By simple 

 compression, which is of little avail towards permanent condensation, 

 on account of the elasticity of substances, but may still however be 

 of some assistance. 2. By the contraction of the coarser, after the 

 escape or departure of the finer parts of a given body ; as is exempli- 

 fied in induration by fire, and the repeated heating and extinguishing 

 of metals, and the like. 3. By the cohesion of the most soHd homo- 

 geneous parts of a given body, which were previously separated, and 

 mixed with others less solid, as in the return of sublimated mercury 

 to its simple state, in which it occupies much less space than it did in 

 powder, and the same may be observed of the cleansing of all metals 

 from their dross. 4. By harmony or the application of substances 

 which condense by some latent power. These harmonies are as yet 

 but rarely observed, at which we cannot be surprised, since there 

 is little to hope for from their investigation, unless the discovery of 

 forms and conformation be attained. With regard to animal bodies, 

 it is not to be questioned that there are many internal and external 

 medicines which condense by harmony, as we have before observed, 

 but this action is rare in inanimate bodies. Written accounts, as 

 well as report, have certainly spoken of a tree in one of the Tercera 

 or Canary Islands (for I do not exactly recollect which) that drips 

 perpetually, so as to supply the inhabitants, in some degree, with 

 water ; and Paracelsus says that the herb called ros solis is filled with 

 dew at noon, whilst the sun gives out its greatest heat, and all other 

 herbs around it are dry. We treat both these accounts as fables ; they 

 would, however, if true, be of the most important service, and most 

 worthy of examination. As to the honey-dew, resembling manna, 

 which is 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. 



