Francis Bacon’s typology of pneumatic substances

For Bacon, spirit in general is a “breath compounded of an airy and a flamy substance” (OFB VI 321). One extreme is that of the air (rather cold and inactive), the other that of fire. But the mixture of air and fire is not mechanical (OFB XII 355); it is a complete mixture (which cannot be simply evaluated in terms of more air/less fire; or more fire/less air, but has a ‘mysterious’ character, OFB XII 352, 376 etc.). In between ‘air’ and ‘fire,’ we have a whole range of spirits: the non-living ones “are nearly consubstantial to air,” while the “vital spirits come closer to the substance of fire.”(OFB XII 354-5) One fundamental principle in Bacon’ natural philosophy is that there is no tangible body devoid of spirit. By contrast, spirits can be ‘free’ or ‘enclosed’ in matter. Meanwhile, spirits also come in all sorts of shapes and forms: and although Bacon sometimes attempted classifications of pneumaticals (i.e. according to their rarity in HDR) it is clear that their diversity resist any form of unique classification.

In the late natural histories, one can find series of experiments which seem to attempt to classify pneumaticals according to their properties. In some cases, the classification takes into consideration observational properties of pneumatics (hence, the resulting ‘classification’ will be called ‘phenomenological’). In some other cases, (esp. Sylva) the principle of classification seem to be the prevailing process (i.e. physical classifications). There is arguably also an attempt to divide spirits and matter in metaphysical terms.

It is not only that these classifications are not unique, they are also overlapping. However, the recurrence of such attempts to classify spirits in the late natural history seem to signify that Bacon was persuaded of the importance of achieving some form of classification, or typology of pneumatic substance.

Meanwhile, Sylva constantly insists on the diversity of spirits and the diversity of properties characterizing spirits. Spirits are “nothing else but a natural body, rarefied to a proportion, and included in tangible parts of bodies;” in addition, they are many differences between spirits: “they be no less differing one from the other than the dense or tangible parts.”(SEH II 381)

Phenomenological classifications

  1. Classification of spirits according to their rarity (HDR)
  2. Classification of spirits according to their heat (sources of heat, how the heat is processed…) (OFB XII 359)

Close distillation (forcing matter/spirit to react to heat in a close container) (SS I 99), and other experiments with closed containers destined to mix air and flame or watery and oily

  1. Classification of spirits according to the qualities of the mixture of air and flamy (which gives it empirical characteristics such as “greediness,” “lassitude” …).

Physical classifications

  1. Classification according to the organization of spirit in matter (branched, cells, cut-off)
  2. Classification according to the even/uneven distribution of spirit in matter and the fineness of the spirit AND/OR strenght[1]
  3. Classification according to the processes that gets activated

Spirits are said to be the causes of all processes (SS I 98) (but whether a process or another takes over is also a property of spiritual substance?)

Classification in terms of activity (resulting from the activated appetites)

[1] Spirits “weak” “clinging loosely, … practically consubstantial with plain air,” “dwelling mainly the outer parts of the body.;” “transient guests” in bodies – Versus spirits “stronger,” “further inside,” “submerged and buried deeper in the solid parts of the thin.” (OFB VI 291) Also, there is a rule in HVM which links the even/non-even distribution of the spirit with its properties/activity – abundance of spirit non-evenly distributed makes the spirit more predatory OFB XII 361.

Metaphysical classification (?)

Spiritus vitalis/Spiritus mortualis (HVM, OFB XII 351)

(Also: (DVM OFB VI 352-3) – vital spirit, peculiar to living things OFB VI 357 – differs from the other spirits not only because it is differently organized, but because it has an inner warmth and because it feeds upon “the moist parts and joice of the living body” (OFB VI 359))

HVM: Rule/Canon IV: In all living things there are two kinds of spirits: non-living ones (Mortuales) of the kind found in inanimate substances, and the superadded vital spirits.

Vital spirit is something different from all the spirits that exist in inanimate bodies because: it needs aliment, it is somehow closely connected with the body (being ‘in charge’ of the body and all the other spirits), it ‘rules’ the other spirits and the body.

Thus we should know that there exist in flesh, bones, membranes, organs, and every single part of the human body, spirits which pervade them while they live, and which are identical to those which exist in those parts – flesh, bone, membrane and the rest – when they are separate and dead, and identical to the ones remaining in the corpse. But the vital spirit, though it rules and has some consent with them, is very different from them, as it is integral and self-consistent [integralis, & per se Constans]. Now the non-living and vital spirits differ in two main ways: the first is that the non-living spirits are not in the least self-continuous, but are as it were cut off and surrounded by the grosser body which intercepts them rather as air is intermixed in snow or froth. But all vital spirit is self-continuous through certain channels which it pervade, without being completely intercepted. This spirit too is of two kinds: the one is just branched and runs through little thead-like tubes [Ducturs, & tanquam Lineas]’ the other has in addition a cell [Cellam] so that it is not just self-continous but is also gathered together in some hollow space and, relative to the body, in an appreciable quantity; and in this cell is the source of the rivulets which go their separate ways from there. This cell is mainly in the cerebral ventricles, which in humbler creatures are narrow, such that the spirits seem to be diffused through the whole body rather than concentrated in cells, as we see in snakes, eels, and flies whose individual parts still move after being cut away. (OFB XII 351-353)

Although Bacon attempts to reduce this fundamental difference to physical and phenomenological differences, it is not entirely clear that this is a successful enterprise (or an enterprise that can succeed). In principle, the differences are:

  • Of organization (non-living spirits are cut off and not organized) and distribution (within the body; how well distributed are the vein, how far away from the cells etc. see DVM)
  • Of composition (all spirits are a mixture of air and flame, and the living one are closer to the nature of flame, but Bacon emphasizes that this is not a mechanical mixture and hence “when this rule states that vital spirits come closed to the substance of flame, it must be taken to mean that they do so more than the non-living ones, and not that they are more flamy than airy” (OFB XII 355).
  • Of behavior/appetites (the non-living spirits have two appetites/desires – to multiply, and to fly and meet with connaturals; living spirits have more appetites, for example they are “absolutely terrified of leaving its body” – which means that living spirits are “principal” spirits of bodies and they are metaphysically united with their bodies)
  • Of heat/warmth (OFB VI 357)

Another major difference is said that non-living bodies/spirit do not need aliment, while the others do (but, however, spirits in inanimate bodies ‘eat-up’ matter)

DVM: But it is unquestionably the case that among the difference of the spirit there are two in particular which have the greatest importance: for spirits differ in body or in force, for we find that some are more biting, lively and robust while others are duller and weaker. And that very force proceeds either from the nature of the thing, or from the length of time that has elapsed since the death of the body. Alternatively, spirits vary in fraction or comminution, for we find bodies in which the spirtis are more diffused and dispersed so that the portion of spirit in any given part is less than it might be, but other bodies in which the spirts have more space and larger concentrations. But again, we find that the distribution of spirits with reference to their sites is more uniform in certain bodies so that the spirits are diffused more evenly in particular parts of the body; but in other bodies they are distributed less evenly so that the residences of the spirit are more spacious in one place and more confined and circumscribed in another. (OFB VI 282-3)


Hypothesis 1: As with many of his new concepts, Bacon seems to use “spirits” in more than one way; using a range of traditional, loose meanings (spirits are the breath of life, they are the source of activity in the Universe and they originate “in the stars,” there are living spirits and non-living spirits etc.) and a more specific, technical meaning (a class of material substances characterized by rarity, heat (potential or actual heat), active powers, the capacity to diffuse at considerable distances, and other several properties such as greed which Bacon attempts to express in terms of combinations of attributes).

Hypothesis 2: There are small but significant differences between DVM and HVM on the one side and SS on the other regarding the fundamental and derivative properties of pneumaticals. These differences can originate in the fact that in SS Bacon asks different questions and is interested in different aspects of the workings of spirits than in the other two works. Thus, there is no equivalent of spiritus mortualis at work. Meanwhile, there seem to be a distinction between the principal spirit of a body and other spirits which might (or might not) inhabit the same body. The principal spirit can be the living spirit of DVM and HDR. Meanwhile, there clearly are other organized spirits at work in the same body (a scion grafted on a stock poses this problem of two principal spirits ‘fighting’ and one is overcoming the other).

Sylva Sylvarum has a number of experiments which seem to be saying that there is no metaphysical distinction between vital spirits and the others, that there is indeed a merely variation in the mixture of air and flame at work, and that one can simply vary the proportion of the two in the mixture

SS1.30 “although air and flame being free will not well mingle; yet bout in by a body that hath some fixing, they will. For that you may best see in those two bodies (which are their aliments) water and oil; for they likewise will not well mingle of themselves, but in the bodies of plants and living creatures they will.”

Francis Bacon and the use of measurement in experiments

One central component of experimental philosophy is measurement. Various properties, quantities, degrees and qualities were counted and measured with more or less exactitude starting with the early modern period (see for example, the analysis of temperature measurement in A.Borrelli, “The weatherglass and its observers in the early seventeenth century”, in: Claus Zittel, Gisela Engel, Nicole C. Karafyllis and Romano Nanni (eds.), Philosophies of technology: Francis Bacon and its contemporaries, vol. 1 (Leiden: Brill, 2008) 67-130 (Intersections 11/1)). Seen in itself, measurement was almost universally considered a tool meant to improve knowledge and to give strength to different arguments and to rebut others. This attitude was shared by Francis Bacon too, as I briefly attempted to show in a small presentation I have made for the 4th Bucharest Colloquium in Early Modern Science. One can infer this from the following example taken from Bacon’s Sylva Sylvarum:

“It is strange how the ancients took up experiments upon credit, and yet did build great matters upon them. The observation of some of the best of them, delivered confidently, is, that a vessel filled with ashes will receive the like quantity of water that it would have done if it had been empty. But this is utterly untrue; for the water will not go in by a fifth part. And I suppose that that fifth part is the difference of the lying close or open of the ashes…” (Sylva Sylvarum, SEH 34).

There are many other examples of experiments in which Bacon used to invoke the measurement and counting of quantities in order to champion his ideas (see for instance, entries 1, 19, 21, 32, 33, 46, 59, 60, 76, 88, 104-110, 156, 159, 248, 306, 307, 309, 310, 318, 324, 363 etc, to give just few examples taken from the first three centuries of Sylva). Here are two more extended examples:

“Dig a pit upon the sea-shore, somewhat above the high-water mark, and sink it as deep as the low-water mark; and as the tide cometh in, it will fill with water, fresh and potable… I remember to have read that trial hath been made of salt water passed through earth, through ten vessels one within another, and yet it hath not lost his saltness, as to become potable: but the same man saith, that (…) salt water drained through twenty vessels hath become fresh… But it is worth the note, how poor the imitations of nature are in common course of experiments, except they be led by great judgment, and some good light of axioms. For first, there is no small difference between a passage of water through twenty small vessels, and through such a distance as between the low-water and high-water mark…” (Sylva Sylvarum, SEH 1-2)


“The continuance of flame, according unto the diversity of the body inflamed, and other circumstances, is worthy the inquiry; chiefly, for that though flame be (almost) of a momentary lasting, yet it receiveth the more and the less: we will first therefore speak (at large) of bodies inflamed wholly and immediately, without any wick to help the inflammation. A spoonful of spirit of wine, a little heated, was taken, and it burnt as long as came to one hundred and sixteen pulses. The same quantity of spirit of wine mixed with the sixth part of a spoonful of nitre, burnt but to the space of ninety-four pulses. Mixed with the like quantity of bay-salt, eighty-three pulses. Mixed with the like quantity of gunpowder, which dissolved into black water, one hundred and ten pulses. A cube or pellet of yellow wax was taken, as much as half the spirit of wine, and set in the midst, and it burnt only to the space of eighty-seven pulses. Mixed with the sixth part of a spoonful of milk, it burnt to the space of one hundred pulses. Mixed with the sixth part of a spoonful of water, it burnt to the space of eighty-six pulses… So that the spirit of wine simple endured the longest; and the spirit of wine with the bay-salt, and the equal quantity of water, were the shortest.” (Sylva Sylvarum, SEH 366)

I propose the following table as a tool for a concise representation of Bacon’s measurement of the continuance of flame:

  • Spirit of wine = 116 pulses
  • Spirit of wine + 1/6 nitre = 94 pulses
  • Spirit of wine + 1/6 bay-salt = 83 pulses
  • Spirit of wine + 1/6 gunpowder = 110 pulses
  • Cube of yellow wax + ½ spirit of wine = 87 pulses
  •  Cube of yellow wax + wine + 1/6milk = 100 pulses
  • Cube of yellow wax + wine + 1/6 water = 86 pulses


This raises a plenty of interesting questions dealing with the way Bacon uses measurement that is worth to be discussed. Here is a tentative list with few of them:

–          What type of measurements does Bacon employ?

–          What type of quantities or qualities is subjected to measurement by Bacon?

–          What other examples of Bacon’s measurements can be represented by such tables?

–          In what theoretical cases is measurement invoked?

–          How important is the exactitude in the measurements?

–          When does measurement help in constructing an argument and when does it help in rejecting other’s arguments?

–          Is measurement an effective tool in building up the theory of matter?

–          Is measurement used independently of Bacon’s theory of matter?

The examples of measurements Sylva Sylvarum presents can be a good starting point for the discussion of these points. Different answers to these questions can also set the stage for a comparative analysis between Bacon’s use of measurement and other philosophical treatments of it.

We would love to hear your comments, suggestions and thoughts on these matters, so please leave us a comment.

Helleborus niger

Among the important plants that Francis Bacon mentions in his experiments in consort touching purging medicines (Sylva Sylvarum, Century I) is the plant of hellebore, considered to be a helpful remedy moving the body to „expell by consent”. Black hellebore is counted among the medicines that have a „loathsome and horrible taste” and by this quality moves the stomach to surcharge and expell. It is interesting to see that Bacon does not consider hellebore to have any occult quality and insists on the fact that purging medicines in general, when better understood, can be properly administered. Thus, the following short presentation on the plant of hel8-Helleborus-Niger-Black-Hellebore-or-Christmas-Rolebore.

The hellebore plant belonging to the helleborus genus has been known ever since antiquity to posses powerful purging qualities. The physicians following Hippocrates used the Helleborus niger, known today as the Christmas Rose and the Veratrum Album-known as the White Hellebore- as diuretic remedies. The Hippocratic physicians, nevertheless, did not acknowledge the pharmaceutical differences between the two plants and used them both for the same purposes, although only black hellebore was later regarded as an efficient cure for obstruction.

Black hellebore has kept its medical importance up until today and it is still listed in some of  the pharmacological manuals. If we look into the pharmacological hand-books of the late sixteen-century, we find out that hellebore was used as a powerful remedy against melancholy and was thought to have the virtue of evacuating molesting humours that would lead to insanity and depression. By the late sixteen century, the difference between the species, their habitat and cultivation methods was already known although the apothecaries still appealed to Pliny and Galen for information regarding the plant. Hellebore was highly esteemed by the „chymick phisicans” too, who would mix it with various other tinctures and oil and alcohol (spirit of wine), a mixture that „could be easily been given to children against the dropsy and all melancholy affections”(du Chesne, 1591) The Alchemists included hellebore in the category of opiate medicines which, according to some of them, proved to be efficient remedies against colics, pleurisy and gout and also able to provoke sleep and appease disease of the respiratory tract and the rheuma. The controversy around opiates is common to sixteen century alchemical debates concerning plants that would have a strong and possibly poisonous impact on the human body. This might be one of the reasons why hidden, occult virtues or qualities have been attributed to it.

Although parts of it, are still used today in homeopathy, the drug made of the hellebore plant is seen to be as highly narcotic.


Bacon, Francis. 1857–74. The Works of Francis Bacon (SEH), 14 vols. edited by James Spedding, Robert Leslie Ellis and Douglas Denon Heath. London: Longman (repr. 1961–63, Stuttgart-Bad Cannstatt: Frommann)

Quercitanus, Josephus. A brief answer of Josephus Quercitanus Armeniacus Doctor pf Physick to the exposition of Jacobus Aubertus Vindonis: Concerning the origins and causes of metals, London, 1591

Prioreschi, Plinio. A History of Medicine, Vol II: Greek medicine, Horatius Press, Omaha,1996

Turner,William. The Name of Herbs in Greek, Latin, English, Dutch and French, London, 1548


Glossary: Appetite

Works: Abecedarium novum naturae (OFB XIII)

Sylva sylvarum (SEH II)

The term ‘appetite’ is a key concept within Baconian natural and moral philosophy, though Bacon never gives a definition or a clear explanation of the term. What can be understood from the several discussions about the appetites is that they are the causes of all actions in nature, both in the inanimate and in the animate realm, and at the distinct levels, from the last particles of matter to the most complex beings. At a micro level, they are also the causes for the existence of compound bodies. From the Abecedarium novum nature it becomes evident that there are four classes of appetites of bodies: for preserving themselves, for bettering their condition, for multiplying themselves and applying their form, and for imposing themselves upon other bodies (ANN, OFB XIII, p. 197). For each of these appetites there are several correspondent simple motions.

Simple motions and their correspondent appetites (ANN):

Of resistance

Of connection

Of liberty                                            self-preservation

Of self-continuity


Of hyle

Of the mayor congregation

Of the minor congregation                bettering of their condition

Of disposition


Of assimilation

Of excitation

Of impression                                     propagation of their nature

Media of motion


Royal motion

Spontaneous motion

Of repose                                           enjoyment of their nature

Of trepidation

In her book Entre el atomismo y la alquimia, Silvia Manzo defines motion as the effect of an appetite and the appetite itself. There is no difference for Bacon, says her, between the tendency to motion (appetite) and the motion itself. Moreover, she discusses the relation between the appetites of matter and the distinct kinds of good propsed in ethics – comun and private (pp. 69-82), both for inanimate, and for animate matter. Tangible matter has two main appetites, to reject vacuum and to consolidate its proper nature. On the other hand, spiritual matter has three appetites: to enjoy its proper nature, to multiply itself upon other spirits and to escape and unite with their connaturals. The main processes in nature (desiccation, liquefaction, putrefaction, and vivification) are the effect of these appetites and the relation between them (pp. 83-85) and between tangible and pneumatic matter.

Most important experiments in SS in which it is given an explanation based on the appetites of matter are: 24 (appetite of continuation in liquids), 33 (appetite of union of dense bodies), 290 (appetite to receive the sound), 293 (appetite of union in bodies), 300 (appetite of the stomach), 336 (appetite of issuing in spirits), 713 & 714 (appetite to expell what strikes the spirits), 716 (appetite to revenge), 763 (appetite not to move), 800 (appetite of bodies to take in others), 831 (appetite in the stomach), 845 (appetite of not discontinuing), 846 (appetite to conitnuity), 931 (venenous appetite of musk, amber, civet), 944 (appetite of contact and conjunction).

Glossary: Spirits


Spirit(s) is one of the most important Baconian terms, featuring prominently in all his works. In the natural historical works (see below) the term is strongly linked/intertwined with Bacon’s ‘pneumatical’ (i.e. ‘spiritual’) matter theory.

Works: Sylva sylvarum (SEH II)

Historia vitae et mortis (OFB XII)

Historia densi et rari (OFB XIII)

De vijs mortis (OFB VI)

For Bacon there are two kinds of matter: tangible and pneumatic. The pneumatic one is also called “spirit” and it is present in every tangible body, being the cause of all actions and visible processes that we observe in the natural world. If the tangible matter is inert, the spirit is very active. In SS experiment 98, Bacon offers a definition of the spirit: “For spirits are nothing else but a natural body, rarefied to a proportion, and included in the tangible parts of bodies, as in an integument. And they be no less differing one from the other than the dense or tangible parts; and they are in all tangible bodies whatsoever, more or less; and they are never (almost) at rest; and from them and their motions principally proceed arefaction, colliquation, concoction, maturation, putrefaction, vivification, and most of the effects of nature.” A similar definition is to be found in HVM: “a body thin and invisible, yet something real with place and extension” (OFB XII, 347-49). it is an important feature in Baconian philosophy that in order to perform changes upon nature, the philosopher has to manipulate the spirits, and this is done through governing their appetites.

There are two main kinds of spirits: non-living (‘mortuales’) and vital (‘vitalis’), the first in inanimate beings and the second in animate ones. There are two main differences between them: spirits of things animate are all continued with themselves, and are branched in veins and secret canals and “the spirits of animate bodies are all in some degree (more or less) kindled and inflamed, and have a fine commixture of flame, and an aerial substance. But inanimate bodies have their spirits no whit inflamed or kindled” (SS, exp. 601). As a consequence of these differences, Bacon finds seven differences between plants and inanimate bodies: firstly, plants are determinate and figurate by the spirit, secondly, pants do nourish, while inanimate bodies do not. Thirdly, plants have a period of life, inanimate bodies not. Fourthly, they have a succession and propagation of their kind, while inanimates do not have it. The last three differences are: metals are more durable than plants, they are more solid and hard and lastly, they are holly subterranean (SS, exp. 601-606).

Within the animate bodies, there are again two types of spirits: those of plants and those of living creatures (animals). Again there are two main differences between them. Firstly, in living creatures the spirits have a cell, while in plants they are organized in branches; and secondly, the spirits of living creatures have more flame and less air, while the spirits of plants are more airy and less flamy, even though, being pneumatic, both are airy and flamy to some degree. But there are also eight secondary differences as a consequence of the two primary ones: a)  plants are fixed to the earth, while living creature are severed; b) living creatures have local motion, while plants do not; c) living creatures nourish themselves from their upper part, plants from below; d) plants have their seed and seminal parts uppermost, while living creatures have them lowermost; e) living creature have a more exact figure than plants; f) living creatures have a greater diversity of organs and inward figures than plants; g) living creatures have sense, plants do not; h) living creatures have voluntary motion, while plants do not. In animate bodies, there are also inanimate spirits, in a constant struggle with the tangible matter and with the other pneumatics. These non-living spirits are responsible for the consumption of bodies and the death of things, while the animates are responsible for the process of nourishment of the body where they live (SS, exp. 607-612 and HVM, OFB XII, p. 351).

The non-living spirits contained in the body want to get out and unite with the air, given their airy nature. This appetite has five consequences: if the spirit is detained in the body, but moves violently there follows colliquation (as in metals), if it moves mildly, it follows maturation and digestion (fruits and liquors), if the spirits protrude a little and the movement is confused, putrefaction follows (as in rotten fruits, flesh, shinning wood), if the motion is ordered, then vivification and figuration follows (as in the creatures bred of putrefaction and those perfect); and if the spirits leave the body there follows desiccation, induration, consumption (as in bricks or in the evaporation of liquids) (SS, introduction to exp. 329).

Sulphur quaternion


Mercury quaternion

Tangibles bodies (with attached   spirits)



Salts (subterranean and in organic   beings)



Oil and oily inflammable substances


Juices of animals and plants

Water and crude non-inflammable   substances


Pneumatic substances

Terrestrial fire


‘Attached’ animate and inanimate   spirits

(in tangible bodies)



Sidereal fire

(planetary matter)

Heaven of the fixed stars


(planetary medium)

Graham Rees, The structure of Bacon’s matter theory,  “Matter Theory: A Unifying factor in Bacon’s Natural Philosophy,” Ambix, 25 (1977), p. 117.

The sources of Francis Bacon’s natural history: vexing questions

Francis Bacon was very much immersed in the humanist tradition: he borrowed freely and creatively from many sources. Writing as he did for a cultivated reader, he rarely identified his source by name or explicit references. In many cases, this was just because any cultivated reader would be expected to know that a certain passage is a quote or a special reading of a well known author/paragraph. In other cases, this was a rhetoric strategy destined to select the readers (those being able to perform the ‘recognition’ task were the ‘more advanced’ readers, the ‘true sons of science’).

Today, this way of writing poses numerous problems: we are far less educated than Bacon’s contemporaries. Meanwhile, it would be very important to recognize Bacon’s sources. In some cases, this would be vital for the understanding of what is at stake in Bacon’s text. Such is the case of natural histories where Bacon freely used ancient and modern authors as sources.

Sources in natural histories

As we have discussed in our previous seminar, and as it became clear from Doina’s presentation of Bacon’s ‘borrowings’ from Della Porta, a large part of Sylva Sylvarum is constructed on a solid basis of ‘facts’ borrowed from natural historical sources. Despite the fact that Ellis, Spedding and Rees have all given  some statistics (30-50 % ‘borrowings’) there is still major work to be done on the identification of Bacon’s sources. It involves a considerable amount of historical and archival research. The more philosophical aspect of it  would be to consider, carefully, how Bacon read, borrowed, and handled the borrowings. In what way he constructed his own experiments from an ancient report or from another experiment taken from Della Porta. In what way he reflected upon the material he used (was he really using it as a ‘fact’? was he reflecting critically on it? At what level were his critical reflections? Theoretical? Methodological? Epistemological?).

Our edition of Sylva

The major challenge in the case of our projected edition is the identification of the sources of a text in which almost every second paragraph refers to an ancient and Renaissance source. We won’t be able to identify all of them. However, even beginning to scrap the surface would be useful, because it would provide the starting point for future contextual (and ‘philosophical’) readings and interpretations of Sylva Sylvarum and other natural histories.

Brunschwig’s “vertuose boke of distyllacyon”

One of the first books dedicated to the art of distillation, Liber de arte distilandi, was published in 1500 by a german physisican, the paracelsian Hieronymus Brunschwig (1450 – 1512). In 1512, Brunschwig publishes an extended version of this small treatise, entitled Grosse Distillierbuch. This book is translated in Dutch in 1519 and then in english in 1527 by Lawrence Andrew. The title of the English translation was: „The vertuose boke of distyllacyon of the waters of all maner of herbes, with the fygures of the styllatoryes : fyrst made and compyled by the thyrte yeres study and labour of the moste cnynge and famous master of phisyke, Maister Iherom bruynswyke : and now newly translate out of Duyche into Englysshe, nat only to the synguler helpe and profyte of the surgyens, phisycyens, and pothecaryes, but also of all maner of people, parfytely and in dewe tyme and ordre to lerne to dystyll all maner of herbes, to the profyte, cure, & remedy of all maner dysseases and infirmytees apparant and nat apparant : and ye shall understande that the waters be better than the herbes, as Avicenna testefyeth in his fourth canon saynge that all maner medicynes used with theyr substance, febleth and maketh aged, and weke.” As the title shows, the book was received as a textbook of pharmacology, because an important part of the book is dedicated to medicinal drinks and cures. But we can also read this book as a textbook of the “know-how” of distillation.

Structure of the book:  The first chapter offers a definition of the science of distillation and an emphasis of its usefulness for medicine. Then a large part of the book is dedicated to a detailed and systematic description of the manners of distilling. Brunschwig is careful in providing the „know-how” of the “instrumentarium” and the actual procedures of distillation. This part includes an important number of illustrations depicting the equipment; that is the vessels for distillations, the gluing substance, the furnals. Brunschwig is careful in offering all the necessary details to put into practice the art of distillation: for example, he is very careful in specifying the type of glass needed (venetian, bohemian glass) so that it can “better withstande the hete of the fyre”. The description of the instrument and the entire distillation laboratory is interesting not only because it provides a lot of details, but also because Brunschwig makes interesting considerations about the technological limits of the operation. He attempts to provide an exhaustive list of vessels  used in distillations: retorts, “glasses with two arms called pelicans” used for recirculating procedures, “blind helms” (a glass lyke a gorde torned into another glass without any pipe), “circulatories” (glasses that are “wide above and beneath and narrowe in the middest”, with a tube projecting from the vessel).  Two other aspects are described in detail: the glueing substance of the vessel and how to build the furnaces, so as to control the fire, for example by ventilation (“to every smoke hole ye shall make a…tappe to governe your fyre). Then, the book considers a number of aspects that are important for a correct distillation of specific substances and for the preservation of the new distilled liquor. The last part of the book (and the widest) is dedicated to showing how to distil each type of medicinal plant; thus establishing what type of distilling procedure is appropriate for a given plant, flower or substance (like vingar, spirit of wine, oils, etc.)

Definition of distillation:

„Distilling is none other thinge/ but one is a purifying of the gross from the subtyle/ or the subtyle from the gross/ each separately from other/ to the intent that the corruptyble shall be made incorruptyble/ and to make the materyall imateryall/ and the quick spyryt to be made quicker because it sholde the soner pierce and passé thrugh by the virtue of his great goodness and strengthe that there is in and sunke and hydde for the concyvyng of the helthfull operacyon in the body of man..” — thus, distillation covers all procedures of separation of bodies and their condensation in liquids.

Brunschwig parallels alchemy with distillation since via distillation the good, medicinal part of a substance is separated from its more impure and harmful part.



Ways and manners of distillation.


Provided the definition, Brunschwig identifies 2 major ways of distilling: with and without fire, or otherwise said with and without cost. Each of these 2 ways, includes several procedures of distillation. These procedures are different experimental set-ups which will be used according to their appropriateness for given substances.  To clarify a substance, heating and circulating are crucial. As such, he is very careful in suggesting ways to control the fire for the distillations with cost either in the construction of furnals, the placement of the stillatories in the furnals.

Distillation without fire: Sources of heat: sun, putrefaction, fermentation

  1. Filtrum distillacio – (distillation with silt).
  2. Folis distillacionem – a form of solar distillation that uses a brinaile (a glass “almost as wide above as beneath”). The brinaile is filled with flowers, a layer of sticks covers its mouth, then it is turned upsidedown and inserted into another glass, glued  and then let in the sun
  3. Per panis distillacionem (fermenting dough)  – a small glass is filled with flowers or herbs and then put in the oven inside the baking bread
  4. Finnie equi distillacionem (distillation in horse dung) –  this is a procedure of doble distillation (first with vessels called cucumber and then in another vessel called pelican). The pelican vessel is useful for recirculating distilaltes, what Brunschwig calls the rectification of waters.
  5. Formyre distillacionem- distillation in anthills (same principle as 4, but the set-up is different).

This procedure can be slow as in the case of the distillations with horse dung or anthills, where the distillation might last from 2 weeks up to months, but also faster forms of distillation as panis distillation.

Distillation with fire:

  1. Balneo marie : “The glass shall be set in warm water, which water shall be in a copper kettle. Take a glass named curcubit, fill the two parts of the same glass with juice herbs, flowers, leaves, fruits or whatsoever it be chopped small, and set the glass upon a ring of lead. Make a bond of cloth three fingers broad about the upper part of the glass. About the same band make four small rings of cloth having four bands coming down to the four rings that be fast on the leaden ring and bind then fast each to the other. Then let the glass with the lid in the water and standing upright and is sure from falling on the one side or the other through the weight of the lid. Then set the alembic or glass and lute it well. Then make fire in your furnace to heat your water and let it be no hotter than you may suffer your finger in it. And have at all times warm water to fill your kettle again, when the water by length of time is wasted through the heat of the fire. For if a drop of cold water touches the glass, it will ruin and break asunder. You shall understand that when it drops no more it is clean distilled. Then you must let the glass stand still in it for to cool, for if you draw the glass hot out of it it would break asunder. It is needful for you also to have a round board with a round hole in the middle to lay about the glass to the intent that it may be the longer warm”.
  2. Distillation in the horse belly – the same procedure as in balneo mariae, but in the water “we put horse tordes…because this is a half degre hoter than in balneo mariae, therefore we may distill harder substances in it”.
  3. Distillation in ashes – “We shall put fine sifted ashes in a cappel 7 inches of thickness. Fill the thrice part of a glass with such substance you want and set it in the ashes, than fill the cappelle with ashes until the third part of the glass be covered and the cappelle shall be open?…for if it were of mere copper, through the force and heat of the fire it would melt. After that set the alembick upon the glass and lute it well upon it with lutum sapiencie. Than make a fire under it that it may drop treatably as if you would tell by the clock. And so continue after the same manner for if it fall faster or quicker the fire is too great; therefore stop the wind holes above and beneath than it shal fall the softer and brenne the lesse and so it that smells the less of the fire.
  4. Distillation in sand – similar procedure with 3
  5. Distillation on fire – distilling directly on the fire; appropriate for aqua fortis “and other strong waters”

Distillation of a substance can be obtained via drying of the herbs (this being the main mechanism behind the solar distillation that Brunschwig proposes), filtration (distillation with silt), fermentation, evaporation, etc. To be noted that although Brunschwig’s description of what distillation is depends on his Paracelsian heritage, how distillation can be effected on various substances does not.







Distillations: what kind of phenomena?

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).


Common elements

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).

Sylva sylvarum: experiments on transmutation of bodies (24.04.2012)

This meeting followed two important directions: 1) the relation between Bacon’s matter theory and Sylva Sylvarum Century I and 2) the particular discussion of experiments 25 to 30 and the way they connect to the other experiments of Century I. This post deals with the second one.

(25) Experiment solitary touching the making of artificial springs. Before touching the actual experiment, Bacon makes a series of observations about experiments in general that are worth being mentioned. First, we are told that although it may be unexpected, Bacon actually continually rejects experiments. Yet, he tells us that “if an experiment be probable in work and of great use, I receive it, but deliver it as doubtful”: a) How should we understand Bacon’s skeptical attitude towards experiments? b) Does he have a criterion (or criteria) for a trustworthy experiment? Bacon’s constant skeptical attitude towards experiment shows that he does not accept experiments at face value. He seems to believe that some experiments do not provide certain knowledge, and that one has to be constantly aware of the experiment’s limitations, and of its construction, and how this tool should be used for the study of nature. A good demonstration of Bacon’s constant preoccupations with the limits of experiments is the first set of experiments from Sylva, where he criticizes Della Porta’s experiment of filtration of seawater as a bad case of translation (from a natural fact to an artificial fact). Thus, Della Porta’s experiment is taken to be an unreliable experiment whose results are not trustworthy. Consequently, for Bacon, what is important is not whether indeed sand can filter the seawater and make it potable, but the fact that Della Porta’s experiment is not actually telling us anything about that particular phenomenon.

The experiment of an artificial spring goes as follows: On sloping land, a hole is dug, and in the hole a trough of stone is introduced. The hole is covered with brakes and sand. What it is observed, according to Bacon’s source (Bacon did not actually perform the experiment), is that even after the rain stops, a spring of water can be observed at the lower end of the trough. According to Bacon, if this is the case, then this phenomenon can be read as a case of transmutation of air into water because it is as if “the water did multiply itself upon the air, by the help of the coldness and condensation of the earth, and the consort of the first water.”

If this reading is correct, then this experiment should be correlated to experiment 27 which discusses the version and transmutation of air into water. This experiment is interesting in many respects. The experiment cites 4 processes through which air is transmuted to water, or in terms of matter theory, a more pneumatic body (the air) into a more tangible body (the water). Those 4 processes are: condensation (as the example of experiment 25), compression (e.g. distillation vapors, dews), the mingling of moist vapours with air (method suggested for testing via an experiment), and via the porosity of bodies. A few things need to be noted. Bacon grades those 4 processes differently: the first 2 are apparent and sure, the last 2 are considered probable, but not yet manifested. Bacon deals with study cases of these processes later on in Sylva, in an entry entitled Experiments in consort touching the version and transmutation of air into water, where the experiments from 76 to 82 deal precisely with how the ‘version’ is acquired via such processes. The immediate question raised is why Bacon chose to (or did he actually choose to?) separate experiment 27 from experiment 76–82. In fact, experiment 29, entitled Experiment solitary touching the condensing of air in such sort as it may put on weight and yield nourishment, seems to fit well with these experiments. This entry touches on also a process of transition of air, as a pneumatic body (the air) to a denser, tangible body. Bacon’s reasoning is the following: usually for sprouting, seeds/plants are buried in the ground and watered. Yet, some things sprout even if they are only left in the air. Bacon proposes to verify whether those things that sprout in the air increase in weight, thus gain some solid mass. If they don’t increase in weight, then the sprouting is just an inner transformation of the body. If they do increase in weight, then Bacon reasons that the only place where this new mass could come from is the air, which in return would mean that the pneumatic air has transformed into a denser, tangible body. Some things to be noted here: the conclusion Bacon reaches here is dependent on his matter theory. Moreover, we could see the experimental proposal that Bacon makes here as a case of a corroborative evidence for the problem of transforming air into a denser body. A second thing: this experiment could also be used to study the problem of whether air can nourish or not, which is nothing other than a case of translation, one of the methods of experientia literata.

Coming back to experiment 27, we observe that this experiment includes some methodological moves worth mentioning: One of the examples given as a case of transmutation of air into water via condensation is the following: “and the experiment of turning water into ice, by snow, nitre, and salt, would be transferred to the turning of air into water”. Provided the 8 rules of EL, this would be a case of production by extension, since as exp. 82 claims, it “is a greater alteration to turn (artificially) air into water, than water into ice”. The same experimental setup is used to study two different problems: whereas the transformation of water into ice is a case of induration of bodies (a process happening in the same body), the transformation of air into water is a case of transmutation (a case of transition from one species to another).

If a connection seemed apparent between these experiments, we couldn’t trace any ways to connect experiments 26 and 28.

Experiment 26 entitled Experiment solitary touching the venomous quality of man’s flesh. This ‘experiment’ establishes a correlation between cannibalism and its malignant effect for human bodies on the basis of a collection of reported instances of cannibalism. In this example, we could say, in modern terms, that instances are corroborated and that a fact (that syphilis/“the disease of Naples” was originally caused by cannibalism) is considered to be probable precisely because of its status as corroborated evidence. On the other hand, we failed to see how this experiment connects to previous ones or how this experiment could be suggested by any of the others that Bacon has presented so far. Even more, we failed to see what theoretical question underpins it. This also happened with experiment 28, entitled Experiment solitary touching the helps towards the beauty and good features of persons, where Bacon discusses how some of man’s features, while growing, can be moulded by pressure.

Proposals for connecting some experiments:

a. experiments 25, 27, 29, and 76 to 82 appear to study a similar problem—whether a pneumatic body can be transformed into a tangible one

b. experiments 17–23 and experiments 76, 77, 79, and 80 deal with  the problem of how pneumatic matter is “trapped” into bodies, e.g. in infusion, in the pores of bodies . We also alluded to a connection of these experiments with the experiments on percolation (in Sylva’s text, experiments 1 to 8. )

Francis Bacon: Sylva Sylvarum, or a natural history in ten centuries, 1627

The purpose of the seminar this semester is to clarify some of the puzzles and mysteries of Bacon’s most widely read and most puzzling work: the posthumous Sylva  Sylvarum.

Sylva Sylvarum or a natural history in ten centuries was published posthumously (but very soon after Bacon’s death in April 1626) by William Rawley. It was by far  the most widely read of Bacon’s writings, at least in seventeenth century England. It went through 10 editions until 1670 and there were subsequent editions up to the end of the century[1]. There seemed to be 17th editions altogether, plus two Latin editions[2] and a French translation[3]. They not always contain the same texts. The first couple of editions contained unpublished fragments and drafts of Bacon’s natural histories, the subsequent editions contained various other material including, from 1660s on, an abridged English version of Novum Organum. All editions contained New Atlantis. However, in the first editions, this is not explicitly stated on the title page (why?).

As the name indicates, Sylva Sylvarum tended to be seen/read as a collection of materials for building the new science (Bacon is slightly modifying the ancient/Renaissance meaning of Silva, creating a new genre, see De Bruyn, 2001. Traditionally, sylva was used to designate the materials necessary for the construction of a discourse/speech. Bacon is not the first one to move the term in the field of natural history/natural philosophy, however). It contains 1000 “experiments” grouped in 10 groups of 100 (centuries). There are two ‘units’ of SS: solitary experiments and experiments in consort. It is not straightforward what is the meaning of ‘experimetns’ in either of the unit: observation, hearsay, travel reports, questions, suggestions, causal explanations and philosophical questions are mixed both in solitary experiments and in the experiments in consort.

A number of manuscripts relating to Sylva are extant. At least one of them indicates, as Graham Rees has shown (Rees 1981), that the text of Sylva was edited and prepared for publication by Bacon himself. In other words, we don’t have a mere heap of remaining experiments and observations that didn’t find their way into Bacon’s late histories, but a book/project of its own, planned to carry forward the third part of the Instauratio (see also Rawley’s claim). Such an interpretation is substantiated by the historical and contextual paper on the publication of Sylva Sylvarum written recently by Colclough (Colclough 2010).

All this is even more intriguing in view of the fact that Sylva is not only very eclectic but also highly unoriginal (at least “locally”); more than half of the “experiments” are second hand reports following ancient of Renaissance authors, some of them obviously untried by Bacon himself and accepted on dubious testimony.

According to Spedding: “a considerable part of it is copied from the most celebrated book of the kind, Porta’s Natural Magic” (II. 326). However, Spedding himself does not identify all the experiments taken by Bacon from Della Porta. A thorough study of the relation between Sylva Sylvarum and Natural Magic awaits to be written.

Moreover, the experiments Bacon ‘borrows’ from Della Porta, Aristotle, Pliny, Cardano, Sandys, Scaliger etc. are substantially rewritten. They are most of the times more ‘general’ and ‘theoretical’ than the punctual observations and experiments of the sources quoted above. Moreover, Bacon integrate such experiments into a larger scale program: they are the kind of experimental activity that would build up a community of experimental scientists (and in this way, they serve as illustration of the activities of Solomon’s House, see Colclough 2010). They are also a storehouse (or program?) for the future experimental philosophy.

.Questions and puzzles:

1. What is Sylva Sylvarum? (Bacon’s experimental notebook, a treatise of natural history, a plan for another kind of natural history than the Latin natural histories, an illustration of the scientific activities of the Salomon’s House…)

2. What is the relation between the materials assembled in this book and other Baconian writings (esp. natural histories)?

3. Is there a secret order of Sylva? (as Rawley claims in the preface?). Is there any order in Sylva whatsoever and if yes, whose plan/order is it? (Is this volume Rawley’s creation?).


[1] Title pages of the subsequent editions don’t agree on their number or on the content, there are various editions claiming to contain “for the first time” materials published in the previous years etc.

[2] Elzevir 1648, 1661, according to Sarah Hutton, 2001 (to check!)

[3] Pierre Amboise, 1631.