BOOK LL] CONDENSATION. 559 



since these spirits retreat, but cannot escape, they consequently 

 meet and are condensed, and are sometimes completely extin 

 guished and suffocated ; although the same opiates, when taken 

 in moderation, by a secondary accident (the condensation which 

 succeeds their union), strengthen the spirits, render them more 

 robust, and check their useless and inflammatory motion, by 

 which means they contribute not a little to the cure of diseases, 

 and the prolongation of life. 



The preparations of bodies, also, for the reception of cold 

 should not be omitted, such as that water a little warmed is more 

 easily frozen than that which is quite cold, and the like. 



Moreover, since nature supplies cold so sparingly, we must 

 act like 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 ascer 

 tain whether there may be any substitutes for cold, that is to 

 say, in what other manner condensation can be effected, which is 

 the peculiar operation of. cold. Such condensations appear 

 hitherto to be of four kinds only. 1. 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 

 exemplified in induration by fire, and the repeated heating and 

 extinguishing of metals, and the like. 3. By the cohesion of the 

 most solid homogeneous parts of a given body, which were pre 

 viously 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 confirmation 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 ob 

 served, 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 recol 

 lect which) that drips perpetually, so as to supply the inhabit 

 ants, 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 oi 



