One way to look at the phenomena described by Bacon in the first century of Sylva is through his repeated affirmations that percolation, filtering, distillation etc. are either produced by the same invisible motion or even identical phenomena. What is the source of such affirmations?
A good number of experiments in Century I are taken from Della Porta, Magia naturalis. Does Bacon take over the same classification of phenomena as Della Porta? Or is there a common and accepted meaning of ‘distillation’ containing phenomena as diverse as filtering, separation due to different specific weights, differences of density, condensation, transmutation etc.?
In fact, at the end of the sixteenth century, distillation is a chemical procedure circumscribing a wide range of phenomena. There are a good number of books dealing with this subject, but here is just one example: Conrad Gesner, Thesaurus…de remediis secretis, Zurich, 1555. A best seller: it was translated into English, French, German and Italian and was often republished until 1600. This book is interesting and relevant, I think, because it belongs to one of the most important sixteenth century ‘naturalists’ , and it ‘belongs’ to the tradition of ‘natural history’. Gesner belongs to the tradition of humanist natural history, he is interested in the natural histories (animals, plants, pharmacy and medicine), he is a doctor (in Zurich) a philologist and a collector. He is also opposed to Paracelsianism.
Thesaurus was published in England a couple of times between 1570 and 1600, under different names: The newe jewell of health (translated by George Backer), London, 1676, and The practise of the new and old physicke, London 1599 (the same translation). It is mainly a book on distillation, where by distillation is understood any procedure through which one manages to separate, from a mixed body, thin, aerial or subtle components. It involves heating, vaporization and condensation but the experimental set-up, the apparatus involved or the principles at work can differ widely, according to what the experimenter wants to achieve.
Definitions of distillation
The book begins with a number of definitions of distillation drawn from ancient and modern authors (Langius, Cardano etc.) – the most general involving any separation of elements or particular virtues from a given mixed body. Distillation can be done in various experimental set up (the simplest: bain marie) and it includes filterying drying evaporation etc. Heating is essential, but boiling is not – in fact, Gesner offers a number of slow distillations where the evaporation takes place in the heat of the sun, or by the rays of light augmented through a mirror or a lens.
Theory of matter
Gesner adopts a very curious ‘mixture’ of ‘Atomism’ and Aristotelian matter theory in order to explain the principle of distillation. Here is a significant passage:
No person needeth to doubt, that all Bodies which growe and take increasement in the earth, are compounded of divers, and in a manner, infinitely small parts (which the Greeks properly name Atomes) of the Elements, and that in those rest differing and contrarie vertues: neverthelesse, under one maner of forme of all the Bodies compounded, as the like appeareth, and is confirmed in that roote of Rubarbe, so much regarded and esteemed in all places, which doth both loose the Belie, and bynde the same, yet this delivereth and openeth the obstructions of the Liver (p. 4).
Since in one single plant or substance (having one substantial form) we can find sometimes different (even opposing) qualities and virtues, the question is how can we separate such virtues and incorporate them in medicines or directly in the human organism. Gesner claims that the experimenter should pay attention to two major ‘principles’: the matter subject to distillation, and the apparatus. In this context, he offers a good number of experimental set-ups and apparatuses for various kinds of distillations, from the most simple (‘drawing waters’ of X) to the more complex (involving transmutations, spirits and immateriate virtues).
Classifications and experimental set-ups
Gesner classifies distillations according to the geometry of the experimental set-ups in ascendent and descendent distillations. Also, according to the kind of heat used, distillation can be produced by the heat of the sun (augmented through mirrors and lenses), by the heat of the fire and by the heat emanating from the putrefaction of matter.
The descending distillation can involve a very simple experimental set up, so simple that we can ‘see’ how many of Bacon’s experiments of filtering, percolation etc. can be developed from there. It begins with simply two pots with the mouths joined and buried in the ground (source: Albertus Magnus’ book on distillation). The upper pot is heated and the lower part is the receiver. There is an entire book on the ‘degrees of heate’ needed (moist heat, gentle heat, strong heat etc.). The geometry can also vary. Although the principle is the same, the stillatory can be placed in vessels of different shapes and forms, sometimes even on the top of a tower (p.16).
There are three common elements of every distillation: the vessel (a glass bulb with a long neck, or a metallic version of the same), ‘the head’ (see figure) and the receiver. The matter to be distilled is put in the vessel, it gets evaporated and reaches the head, where a process of condensation takes place. The result has to be captured by the receiver.
Although heat is involved in all the distillations described, Gesner also mentions the possibility of distillation to be done ‘by the ice’ (28). What is also interesting is that in the second and third book Gesner is fully aware of the importance of the geometry of the experimental set-ups (for ‘catching’ various volatile components of various substances).