Upload
duongtu
View
230
Download
0
Embed Size (px)
Citation preview
Konzept, Inhalt (einschließlich Abbildungen) sowie sprachliche Darstellung dieses Artikels sind urheberrechtlich geschützt. Die Rechte liegen bei PD Dr. Jens Loescher. Die Bildrechte der genannten Archive bleiben davon unberührt. Saarbrücken, den 1. Juli 2012 PD Dr. Jens Loescher Universität des Saarlandes Fachrichtung 4.1. - Germanistik Postfach 15 11 50 D-66041 Saarbrücken
1
Not Theory-laden, not Realistic:
How to see through Swammerdam's Microscope
PD Dr. Jens Loescher Universität des Saarlandes Freie Universität Berlin
Universität des Saarlandes Fachrichtung 4.1. - Germanistik Postfach 15 11 50 D-66041 Saarbrücken
[email protected] http://www.uni-saarland.de/fak4/fr41/germanistik/ [email protected] http://userpage.fu-berlin.de/loescher
Abstract
In this article I will deal with the cognitive practices of the two leading microscopists of the seventeenth century – Swammerdam, Leeuwenhoek – , drawing from Ian Hacking's notion of experimental cognition. Corresponding to this theoretical scaffold I make use of a hint Loraine Daston gave as to material traces of cognitive practices due to reading and writingi.That is why, methodically, I focus on manuscripts in order to track the function of cognitive practices. The manuscript corpus in this article will be the Nachlass of Jan Swammerdam, that is, among others, the papers which constitute the "Biblia Naturae". The Nachlass waspurchased by the Niedersächsische Staats- und Universitätsbibliothek Göttingen on the 27th of September 1784 and is still archived thereii.In section two, I will give a short overview of this manuscript corpus and outline the biographical counterpart of certain traits of Swammerdam's œuvre. In section three, I will elaborate on the theoretical scaffold of my approach. In section four, the cognitive practice of modeling epistemic objects out of magnified images of specimen will be focused. In section five, I will concentrate on the folios of the Nachlass which aid memorizing. Two sidesteps outside the historical narrative proper (to Cajal) will supplement my argument.
1. Introduction .................................................................................................................... 2
2. Swammerdam's Papers................................................................................................... 3
3. Experimental Cognition ................................................................................................. 5
4. Paper Models.................................................................................................................. 8
5. Paper Layers................................................................................................................. 16
6. References .................................................................................................................... 25
2
“Practice — and I mean in general doing, not looking — creates the ability to distinguish
between visible artifacts of the preparation or the instrument, and the real structure that is seen
with the microscope. This practical ability breeds conviction" (Ian Hacking 1985, 137)
“Shapin describes how Leeuwenhoek borrows the prestige of notables to endorse his
observations; but the more elementary fact is that the uncredentialed, socially difficult
Leeuwenhoek achieved authority because of what he saw”. (Catherine Wilson 1995, 171)
1. Introduction
In this article I will deal with the cognitive practices of the two leading microscopists of the
seventeenth century – Swammerdam, Leeuwenhoek – , drawing from Ian Hacking's notion of
experimental cognition. Corresponding to this theoretical scaffold I make use of a hint
Loraine Daston gave as to material traces of cognitive practices due to reading and writingiii.
That is why, methodically, I focus on manuscripts in order to track the function of cognitive
practices. The manuscript corpus in this article will be the Nachlass of Jan Swammerdam, that
is, among others, the papers which constitute the "Biblia Naturae". The Nachlass was
purchased by the Niedersächsische Staats- und Universitätsbibliothek Göttingen on the 27th of
September 1784 and is still archived thereiv.
In section two, I will give a short overview of this manuscript corpus and outline the
biographical counterpart of certain traits of Swammerdam's œuvre. In section three, I will
elaborate on the theoretical scaffold of my approach. In section four, the cognitive practice of
modeling epistemic objects out of magnified images of specimen will be focused. In section
five, I will concentrate on the folios of the Nachlass which aid memorizing. Two sidesteps
outside the historical narrative proper (to Cajal) will supplement my argument.
3
2. Swammerdam's Papers
According to the biographers Lindeboom and Ruestow Jan Swammerdam, who was born in
1637 and died in 1680, needs to take the tragic part on the stage of the scientific revolution of
the seventeenth century. Although trained in the academic subject of medicine in Leiden
Swammerdam suffered from a precariously modest material basis which in fact was supplied
by his father until the latter’s death. Because Swammerdam inherited part of the estate his
financial difficulties seem to have been eased somewhat for the remaining years of his life.
But there must have been another troublesome aspect: Swammerdam was probably isolated
from social life to such a degree that his scientific work served as a sublimation of this deficit.
And Swammerdam was a man of spiritual longing; thus he was caught in the current of the
sect of Antoinette de Bourignon who took to the Netherlands after having been expelled from
France. There is indeed, as his postmortem ‘friend’ and editor Hermann Boerhaave stated, a
basso continuo of worship in his scientific writing, an exhilarated voice praising the creator.
His working style as a scientist did resemble that kind of ardent and possibly self-denying
rigueur. As Boerhaave describes it, Swammerdam must have worked many hours in the sun
dissecting specimen and observing them beneath the microscope with the sweat pouring down
his face, spending the nights taking down notes on what he had seenv. Even in Boerhaave's
sober report the picture resembles that of a religious martyr.
Still, Swammerdam was a trained academic, and there is, somewhat paradox, a host of
allusions, rhetorical topoi, and metaphors adding to the somewhat hypertrophic character of
his letters to the life-long friend Thevenot. Boerhaave who got in possession of the
Swammerdam manuscripts, which Thevenot originally was supposed to publish according to
Swammerdam’s last will, finally managed to edit the material in 1737/1738 under the title
4
‘Biblia Naturae’. Most of the manuscripts were written between 1665 and 1680, some sixty
years earliervi.
Boerhaave did have a hard job. Some papers are written very carelessly (indeed during
experimentation or under conditions of fatigue or bad eyesight) and Swammerdam changes
abruptly between French and Dutch, sometimes in the middle of the sentence. Basically, the
material which is preserved consists of text segments, letters, and copper plates which are
bundled together by folding or glue. Concerning size and quality of paper the missives, for
example the "Tractaat van de beyen" or "L' éphémère", are clearly discriminable. These
manuscripts were transferred into the 'Biblia Naturae'-corpus without major alterationsvii.
Meticulous care was dedicated to the inventories of the illustrations: by Swammerdam, by
Thevenot, finally by Boerhaave. That is why the ‘Biblia Naturae’ contains some fifty pages of
short explanations of the copper plates, a ‘glossary’ of the epistemic objects to be seen which
is the most detailed of its time. There are plenty of corrections and commentaries of
Boerhaave’s hand in the manuscripts, among them two pages of a proof read of the Biblia
with dozens of correcting marks at the margin touching only the Dutch, not the Latin text
segment (fascicle 7) and about eight corrected copper plates which are bundled together in a
pack with most of the other figures of the Biblia-corpus (fascicle 26).
5
3. Experimental Cognition
There are a couple of ‘old chest-nuts’ in research on microscopy, as Liba Taub has put it
(Taub 1999, 732), one of them being the "lost eighteenth century"viii. Indeed, passing the
1680s there is one lonely watch tower of microscopic research: Antoni van Leeuwenhoek who
incessantly sends his missives to the Royal Society. When Gerard LE' Turner stated that the
microscope is "an instrument in search of a theory" (LaBerge 1999, 116), he supposedly
pointed to the fact that, in the seventeenth century, there is no theory for the epistemic
phenomena encountered with the microscope (in contrast to the telescope). There is no grasp
of cellular structures, there is no understanding of microorganisms, there is a very limited
theory of laval metamorphosis – still over-formed by ‘spontaneous generation’ –. The
preference of Newtonian atomism, basically: particles being subject to the laws of gravity, of
mass, of attraction and repulsion forms an undercurrent in quite a few observations of
Leeuwenhoek. That 'Newtonism' proved utterly dysfunctional for microorganisms. On the
whole, theory does not keep pace with experimental output. Therefore, that is the old
chestnut, the experimental output ceases until the beginning of the nineteenth century.
If this is so, why did microscopic observation flourish in the first place? It is not
theory-laden and it is not realistic in the sense that we simply ‘see through the microscope’, as
a famous Hacking-sentence runs. What, then, enabled the five great microscopists of the
seventeenth century — Leeuwenhoek, Swammerdam, Hooke, Malpighi, Grew — to get
started and go on with their work? It is precisely because there is no 'theory-ladenness' and no
‘reality’. Observation and apprehension of the microscopist need to be adjusted ‘from within’
to the environment of the experimental setting (instrument, specimen, light). It is cognitive
6
practices which do the job of closing the lacuna between thing observed, image seen, and
construction of meaning.
There are three major notions of cognition in experimental situations in the
literature: one is the mentioned 'transcendental' approach. The second line of argument rests
on the various versions of distributed cognition, ranging from Ludvik Fleck to Edwin
Hutchins’ 'Cognition in the Wild’ix. Now it is individuals making use of cognitive practices in
order to be able to construct epistemic objects. But these individuals ‘see’ according to
collective schools, mental models or pragmatic frames. Third, in a kind of Sennett-like-
approach a materialistic hyperrealism is put forward: There is a 'dialogue' between the thing to
be worked on and the operating person — sometimes, in the robust version of recently
evolving ‘engineering studies’, the material ‘talks back’ and guides scientific innovationx.
Judging from the manuscripts, I would like to put forward here a brand of
experimental cognitionxi. In the experimental situation the scientist activates certain cognitive
practices which help him bridge a mass of (sense) data and the epistemic thing unfolding. The
transition from ignorance to the "Aha-experience" is in essence a private onexii.
It is important to keep in mind that collectivist and constructivist accounts of cognition
have no terminological armature for the description of specific experimental situations. It does
not make sense to shy away from a 'psychological' or rather: 'processual' brand of cognition,
especially if the material traces on the manuscripts incourage such a viewxiii. I build on
Lorraine Daston’s work on cognitive practicesxiv, but I wish to shift the focus from her a
priori perspective of the epistemic relation between the scientific object and the observing
scientist to specific, ad hoc, 'productive' experimental situations. Cognitive practices are not
the exclusive domain of a 'transcendental scientific self', but also influence singular, 'unique'
encounters between object and observer. They are processed "from scratch" (combined,
transformed, hierarchized) based on environmental, material, and experimental constraints.
7
Since cognitive practices evolve, rise and perish due to an 'improbable' interrelation
of collective thinking styles, transformed ethical habitus, and ad-hoc experimental situations
they need to be described on their specific historical level. Of course, I follow the "anti-
Koyréan" caveat, or rather: taking the terms 'cognition' and 'practice' seriously does not mean
to succumb to a-historical givens. On the other hand, there is no way of escaping the fact that
there is an individual shadow bending over the microscope at the laboratory at night; an
individual in a unique experimental situation. There is no a priori for this kind of practice.
In January 1665, the science-afficionado and diarist Samuel Pepys turned out to be
unable to “come to find the matter of seeing anything by my microscope” (Jardine 1999, 43).
Johann Franz Griendel gave evidence for a very special spontaneous generation in his
“Micrographia nova" (1687): Out of a drop of water beneath the magnifying glass the body
and the head of a frog emanated during the time span of three days. This is evidently
cognition run wild. A theory or thinking style is implemented into the experimental situation
or rather: it is forced on it. There is precisely no cognitive practice involved which would be
of help with isolating segments of the image perceived, forming models of epistemic objects
out of the sense data and memorizing the experimental outcome for future replications.
Consequently, for the skilled microscopists in question here, I suggest three types of cognitive
practices:
'Data Cut'. Isolate segments of the image of the experimental object. Apprehension
of ‘real’ structure and of artifacts.
Modeling. Imaginative forming of 'Gestalts’ with the data.
'Preparation of the Manuscript Page'. Layers of past experimental episodes
superimposed and condensed on the script carrier.
8
4. Paper Models
The microscope is the small brother of the telescope. The ‘early’ microscopes were double-
lens, ‘Keplerian’ optical systems. Of course, microscopes up to the beginning of the
nineteenth century produced a multitude of artifacts: mostly due to spherical and chromatic
aberration. The former is caused by the fact that the refraction at the edge of the lens is greater
than in the center. The latter is pointing to the problem of varying degrees of refraction of
light of different colors. This effect is particularly devastating in compound microscopes
where the light is refracted several times and the image of the specimen therefore is
surrounded by color fringes.
One school of microscopic invention, the English, headed towards more complicated
apparatus, especially with Christopher Cock, Neremiah Grew and, of course, Robert Hooke,
who nevertheless grudgingly conceded that though “offensive to his eyes, tis possible with a
single Microscope to make discoveries much better than with a double one, because the colors
which do much disturb the clear vision in double microscopes is clearly avoided in the single”
(Fournier 1996, 13). Hooke relates to the Dutch current of simplification of the instrument, a
purified version of instrumental magnification, consisting basically of a single spherical lens.
The design of the typical Leeuwenhoek-microscope would be this: a brass block stage
of rectangular cross-section, a specimen pin, a main screw, a single lens. And that is it. Were
it not for the extraordinary quality of the lenses Leeuwenhoek was able to grind (in some of
the nine surviving microscopes modern calibration methods have demonstrated a
magnification up to 120 times of the specimen original) one could speak of spectacles with
some additional equipment.
Swammerdam and Leeuwenhoek lay open the construction of their instrument,
pointing to Hooke’s lengthy description in the ‘Micrographia’. Let us turn to Swammerdam,
to be precise a letter, dated 30th of March 1678 (Lindeboom, 1975, Letter 18, p.98).
9
Figure 1
Swammerdam Nachlass Göttingen, 2°Cod MS med. et hist. nat. 102, Conv.1, Fasc.3, p. 3
recto.
Ik sende ue hier nevens een van myne microscopie glasen, dat tusschen beiden van groote ist, gy
kunt het eens proberen, want ik weet selfs nog niet of het heel goet is. Men gebruykt die al hier
op dese wijs (aa) de tubulus vitreus vol met bloet, (b) het glas van het micros(co)pii, dat in
swaart hout (c) staat (D) het koper beugelken, dat buygen kann, en dat in het hout van het
microsc. heeft de plaats daar syn beweging is (EE), een kopere tubulus (ff) die heen en weer
beweegt en in een gedrayt hout dat swart is, vast staat G. nog een stuxken koper H dat op de
kopere tubulus heen en weer beweegt. en waar op het koper EE vast geklonken is, en rontzom
draijt.
I send you enclosed one of my microscope glasses which is of a moderate size, you may try it
some time, for I do not yet know whether it is very good. One uses it here in this manner (aa)
the tubulus vitreus full of blood (b); the glass of the microscope standing in black (or heavy)
wood (c), the little flexible copper clasp (D9 that has its place in the wood of the microscope
weher ist movement is EE; a copper tubulus (ff) that moves to and fro, and is fixed in a turned
piece of black wood, G. Another little piece of copper H moving to and fro on the copper
tubulus; the copper EE has been rivetted on it and turns around.
11
Apart from the beautiful drawing of the compound microscope, this is just the 'usual'
instrument description with paper tools (AA, BB) which link depiction and text. We know
this technique from Boyle's or Hooke's textbooks. Text-depiction pairs simulate the shift from
instrument to object to data table for the novice reader as I have outlined elsewherexv. There is
a deliberate instructing touch to this presentation technique concerning cognitive practices.
Nevertheless, reflections on the instrument, the microscope, also point to the gap between
object and artificial image or artifact ("for I do not yet know whether it is very good"). In
January 1678, two months before his didactic aside to Thevenot, Swammerdam writes
(Lindeboom 1975, Letter 14, 83):
“Nowadays, I believe, the magnifying-glasses are in perfection, and so are the instruments that
one has to use. And I found a very easy way to make all that myself, and I could teach it to
another person in a quarter of an hour. My glasses with which I see the greatest object, are not
greater than as I picture here. But the object should be so near to it that it is nearly touched by
the glass. ".
I believe that you will already have understood how the blood of a man, being outside its veins,
appears as small globuli in this manner. And it remains then still fluid. So that with a
magnifying glass nothing more beautiful is to be seen than that, especially if one lets it run to
and fro, as when every globulus separately is revolving like a circle. One ought to communicate
all these methods and also how one sees this and makes the magnifying-glasses, like you
sometimes say I had promised. However, Sir, a man cannot do everything”.
In Dutch even clearer, Swammerdam explicitly states that there is a need to communicate
‚how to see’ with the microscope. „Alle deese manieren en ook hoe men dit siet en de
vergrootg(l)asen maakt, behoorde men te communiceren”. – Can one communicate how to
see through a microscope? There are three ways: first a 'thick description' of the epistemic
object that is (to be) seen. Second, a depiction of the microscopical image that is objective,
but also didactic. Third, a model, mental or real. The first was done by Swammerdam and his
successors as we have seen with the glossaries. Drawings were Hooke's and Leeuwenhoek's
12
domain or rather their draughtsman's'. In some cases the microscopist himself sketches in actu
while observing the specimen beneath the microscope (Hooke, later Cajal). Leeuwenhoek, at
last, had a wax model of blood corpuscles ready at hand for visitors of his ‘interactive science
museum’ (Taub 1999).
Let us focus the object Swammerdam chose: Red blood cells. Erythrocytes have a
precarious status between theory-ladenness and 'reality' in the seventeenth century.
Leuuwenhoek dealt with them from the beginning of his scientific career until the end of his
life, some fifty years later. He examined his own blood, the blood of frogs and fish, of dogs,
cats, and a lot of other mammals. According to the ruling opinion of his time red blood
corpuscles were supposed to be globules, that means round and soft fluid filled bladders. That
is why they were supposed to be spinning especially when they were isolated from the serum.
The point is that healthy erythrocytes in mammals are swollen disks with a concave
depression in the middle of each side; they are not spherical, but oval and flat. Now,
Leeuwenhoek was struck time and time again by precisely this oddity when examining red
blood corpuscles. They seemed to have a nucleus (‘a light’), they seemed to be flat rather than
round. The mindful scientist – and Leuwenhoek's verba cogitandi abound in his letters – is
confronted with the question, if he has to adapt the theory or the 'cognitive' strategy or if the
observed phenomenon is an artifact. To find out, Leeuwenhoek had his draughtsman depict
the microscopic image directly without his supervision.
13
Figure 2. Taken from Edward Ruestow: "The Microscope in the Dutch Republic. The
Shaping of Discovery", p.195.
On the image the corpuscles appear with an oval shape. In figure four, which was, according
to Ruestow, supervised by Leeuwenhoek, they are clearly globules. "How one sees this"
exactly refers to the cognitive practice of isolating the relevant segment of the image: a data
cut at the right moment. In the no-mans-land between lack of theory and unreliable instrument
the microscopist resorts to a cognitive – and material – practice eventually leading to a
sustainable hypothesis.
The neuroanatomist Ramón y Cajal who ‘invented’ the neuron around 1900 had a
much better instrument. As an award, he was donated a Zeiss microscop with a stereo-
photographic device built in it. Cajal also worked with the camera lucida, which assisted him
with drawing the image while observing the object in the microscopexvi. Cajal – the would be
artist – drew most of his specimen as they appeared beneath the microscope, as projected by
the camera lucida or on the photograph. There is evidence that in certain cases he sketched the
image with his free right hand while looking into the microscope (Garcia-Lopez, Garcia-
14
Marin, Freire 2010). It is the drawings he published as illustrations of his findings more than
photographs.
Figure 3. Taken from Garcia-Lopez/Garcia-Marin/Freire 2010, p.4.
15
Looking at the images the drawings seem to be at variance with the photographs in certain
respects. The drawing transforms the image into a model which imposes a "bias" on
perception, an implicit aesthetic judgment marking certain features and aiding memorization.
The faithful eye and the mindful handxvii of the drawing observer produce an image the
structure of which is more discernible than that of the photograph.
Returning to our red blood corpuscles and thus to a period much earlier I think we are
prepared to see now that isolating and modeling in fact are congruent. By isolating segments
of the image the microscopist is modeling. By both material and cognitive practices he is
communicating the unfolding epistemic object to himself and to others.
16
5. Paper Layers
‘Mental models’ in early science, as a material practice on paper? Yes, especially in relation
to text-depiction-pairs which abound in Swammerdam's letters to Thevenot, not only in the
context of instrument descriptions. In Letter 18, part of which we have analyzed already,
Swammerdam describes a beehive to Thevenot and depicts it (Lindeboom, 1975, Letter 18,
p.99).
Figure 5
Swammerdam Nachlass Göttingen, 2°Cod MS med. et hist. nat. 102, Conv.1, Fasc.2, p.23
recto
I find that the cells (in Dutch: cellule. My remark) of a beehive are not exactly equally big, but
that they differ often; moreover that in every beehive great irregularities do occur, sometimes
the 'cottages' are twice as long as the others wherein they are collecting honey. Moreover, they
are sometimes curved, and sometimes oblique, and are not always arranged in a regular way;
this all contrary to your concept. However, generally spoken the architecture in it is wonderful,
for example to make a hexagon, they divide a circle (aa) in this manner, equally in six parts, that
sometimes do not differ a whit and then the whole building stands on these admirably regulated
lines by which Archimedes undoubtedly would have been dumbfounded, if he had seen it”
18
Obviously, the ‘geometrical’ lines, Archimedes would have been dumbfounded by are not on
the microscopic image. Swammerdam adds them to illustrate to his friend what he means by
the ‘architecture’ of the object. A single image is transformed into a model. This model is part
of the semantic shorthand the observer/experimenter uses to communicate to himself and the
reader the structure of the epistemic object.
Another phenomenon that is striking with Swammerdam's papers are about eight copper
plates from the ‘Biblia Naturae’-corpus with handwritten commentaries of Boerhaave. Often
segments of the illustration are highlighted with remarks on misrepresented size, that is: the
comments take pains at communicating correctly 'how this is to be seen'. Now, what is
amazing here is that Boerhaave – acting as a historiographer and preserver of texts written
fifty years earlier – corrects the illustrations according to the present state of the art.
Swammerdam’s text, as Boerhaave was aware, was a historical document already in his times.
The solution for this paradox must be: Boerhaave does not alter the images with relation to
the present state of the art; he corrects them with regard to what he thinks Swammerdam has
seen. The cognitive practices of Data Cut and Modeling need to be communicated as if
author, editor and reader were on the historical level of the experiment.
Figure 4. Swammerdam Nachlass Göttingen, 2°Cod MS med. et hist. nat. 102, Conv.2,
Fasc.26, p. 17 recto.
20
Let us return to Cajal once more. In the English translation of his “Reglas y Consejos sobre
Investigación Cientifica: Los tónicos de la voluntad" (1897) we read:
"To bring scientific investigation to a happy end once appropriate methods have been
determined, we must hold firmly in mind the goal of the project. The object here is to focus the
train of thought on more and more complex and accurate associations between images based on
observation and ideas slumbering in the unconscious – ideas that only vigorous concentration of
mental energy can raise to the conscious level". (Swanson/Swanson 1999, 33).
It might be useful to step back for a second. What Cajal apparently suggests here (and is
echoed in Poincaré’s and Jacques Hadamard's reflections on innovation in mathematics for
instance) is a leading role for – mental models. 'Realistic' observation is mentally
reconstructed. Models of the observed specimen are remembered, combined with each other
and with altogether different concepts of the ‘subconscious’. That way scientific innovation
takes place.
With Swammerdam there is, in contrast to Leeuwenhoek’s manuscripts, an amazing
method of organizing this innovation on a material level: layers of text, text-depictions pairs
and comments on the script carrier. Some parts of the Nachlass look as if Swammerdam had
done a preparation of the manuscript page in the sense that it is fixed, 'stained', 'condensed' for
'observation' (reading it again). Thus the cognitive practices of superimposition and
condensing are ‘externalized’ on the palimpsest of the manuscript whereas in the textbook,
the Biblia, they are ‘verbalized’. As an example I suggest Letter 37 dating from September
1679 (Lindeboom 1975, 156).
21
Figure 6
Swammerdam Nachlass Göttingen, 2°Cod MS med. et hist. nat. 102, Conv.1, Fasc.2, p.9
recto
As to the contents of my letter to you four weeks ago: it contained mainly some observations
about the fern which I had made already in the year 1674 and earlier; however, it was neglected
afterwards, please do note that. In my last observations, where I said that the folliculi seminum
are enclosed in some leaflets: that has been written only from a weak memory and although I
looked at it in time; all the small ‘cottages’ were already open, so that I had not all the requisites
at hand that I needed to recognize my error. Now it is like this that the first principles of the
tubercula filicis have the figure of a heart A, which, being like a common membrane or a small
purse, embraces all the follicles equally and hides them. Within this common membrane I have
counted distinctly 178 follicles in some of them. The colour of this ‘tunica investiens' is green in
the beginning, then it gets the colour of muscus on account of the translucent seed ‘cottages’,
and finally it withers, shrinks and bursts. (...) I judge it necessary, Sir, that you add all this to it.”
23
Performing an autopsy of the script carrier – the term borrowed from editorial philology
might be in place with the ardent dissectionists here – it is certain that the segment containing
the drawings is of different paper quality than the rest of the script carrier. Consequently, I
think that the illustrations actually are not drawings, but part of a copper plate print inserted in
the letter paperxviii. The demarcation line of copper plate paper and letter paper is clearly
discernible on the original.
Figure 8
24
Taking the text into consideration we find an apt explanation for this ensemble of material
layers. Apparently, Swammerdam has dealt with seeds of ferns some four years earlier and
the copper plates were made then. After that, the material was ‘neglected’, a formulation
Swammerdam is sure to insert in the text post hoc. So, when Swammerdam writes to
Thevenot in August 1679 about the seeds of fern he communicates his observations from
"swakke memorie" — no small wonder given the fact that the observations took place four
years ago. Also the scientist lacks the ‘requisites' for proper observation, the technical
environment is not suitable “om mijn misslag te erkennen”, “to recognize my error”. At this
point there is a clear mark for a new paragraph on the script carrier; usually, Swammerdam
does not set paragraphs apart. 'Het is dan aldus’, ‘Now it is like this’ introduces the correction
of the bad memory in the ensuing text-depiction-pair. Now, the 'old' observation represented
in the illustration and the ‘new’ observation represented in the text merge: in the literal sense,
on the manuscript page. Finally, Swammerdam takes pains to advise Thevenot to “add all this
to it”, that is add the ‘new’ information which was supplied (in part) by the ‘old’ copper plates
to the recent faulty description of the experimental object.
Concluding, I would like to recapitulate shortly what kind of process is taking place
here. The mental images which were accomplished by observation, according to Cajal, are
brought in juxtaposition to the real images depicted in the copper plates. Memory fails, but the
material traces preserve the objective data. Thus a new combination of material and mental
traces unfolds in the text-depiction-pair. This new combination or model is superimposed on
the old faulty one.
Comparing the three manuscripts of this section we end up with a clear picture of
experimental cognition. First, a model is designed. Then, consecutive experimental episodes
are documented in layers on the script carrier. Eventually, these layers are merged in the form
of a palimpsest. An epistemic thing unfolds. It can be seen on paper.
25
6. References
Cajal, Ramón y: "Advice for a young investigator", ed.b. Neely Swanson, Larry W. Swanson,
Massachusetts: MIT Press, 1999.
Cobb, Matthew: "Reading and writing the Book of Nature: Jan Swammerdam (1637-1680),
Endevaour, vol.24/3, 2000.
Fournier, Marian: "The Fabric of Life. Microscopy in the Seventeenth Century", Johns
Hopkins University Press, 1996.
Garcia-Lopez, Pablo; Garcia-Marin, Virginia; Freire, Miguel: "The Histological Slides and
Drawings of Cajal", Frontiers in Neuroanatomy, vol.4, 2010, pp.1-16.
Hacking, Ian: "Do we see through a Microscope?", in: Images of Science. Essays on Realism
and Empiricism, ed. b. Paul M. Churchland, Chicago, 1985.
Jardine, Lisa: "Ingenious Pursuits: Building the Scientific Revolution", London, 1999.
LaBerge, Ann: "The History of Science and the History of Microscopy", Perspectives on
Science, vol.7/1, 1999.
Lindeboom, J.A.: "The Letters of Jan Swammerdam to Thevenot", Amsterdam: Swets &
Zeitlinger, 1975.
Ruestow, Edward G.: "The Microscope in the Dutch Republic. The Shaping of Discovery",
Cambridge, 1996.
Schickore, Jutta: "Doing Science, Writing Science", Philosophy of Science, 75, 2008, pp.323–
343.
Schickore, Jutta: "The Microscope and the Eye: A History of Reflections, 1740–1870",
Chicago: University of Chicago Press, 2007.
Taub, Liba: "Heroes of Microscopy and Museology", Studies in the History and Philosophy of
Science, vol.30, nr.4, 1999, pp.729-744.
Wilson, Catherine: "The Invisible World. Early Modern Philosophy and the Invention of the
Microscope", Princeton, 1995.
i Lorraine Daston: „Taking note(s)“, Isis, vol. 95, no. 3, 2004, pp. 443-448.
ii 2° Cod. Ms. med. et hist. nat. 102. Convoluts one and two (in the followong: conv.). The Swammerdam papers
have been part of the 'Nachlass' of a Gualt van Doeveren, before they were purchased by the university library
Göttingen. The university of Göttingen was founded in 1732 and had a focus on natural philosophy/science from
the beginning.
26
iii Lorraine Daston: „Taking note(s)“, Isis, vol. 95, no. 3, 2004, pp. 443-448.
iv 2° Cod. Ms. med. et hist. nat. 102. Convolutes one and two (in the following: conv.). The Swammerdam
papers have been part of the 'Nachlass' of a Gualt van Doeveren, before they were purchased by the university
library Göttingen. The University of Göttingen was founded in 1732 and had a focus on natural
philosophy/science from the beginning.
v "Bybel der Natuure, door Jan Swammerdam, Amsteldammer. Of Historie der Insecten, tot zeekere zoorten
gebracht: door voorbeelden, ontleedkundige onderzoekingen van veelerhande kleine gediertens, als ook door
kunstige kopere plaaten opgeheldert. Verrykt met ontelbaare waarnemingen van nooit ontdekte zeldzaamheden
in de natuur : II. deelen / Alles in de Hollandsche, des Auteurs Moedertaale, beschreven; hier by komt een
voorreeden, waar in het leven van den Auteur beschreven is door Herman Boerhaave, Professor in de Medicyne
&c. &c. De Latynsche Overzetting heeft bezorgt Hieronimus David Gaubius, Professor in de Medicyne en
Chemie". Leydae: apud Isaacum Severinum, 1737. See Boerhaave's 'Vita auctoris', p.5 passim. The two volumes
are in Dutch and Latin; as it is mentioned in the Titula Gaubius was the translator.
vi A minor note: I found an interesting manuscript of a letter of Leeuwenhoek to Thevenot in the corpus which
has been misplaced (fascicle 25). In this letter Leeuwenhoek claims that he, not Harvey was the first to discover
blood circulation. As far as I can see this letter has not been noticed in the Leeuwenhoek research-community.
vii The "Tractaat von de Beyen" was inserted on pages 367-538 of the Biblia.
viii The term was coined first by Brian Ford in 1973.
ix Ludwik Fleck: "Entstehung und Entwicklung einer wissenschaftlichen Tatsache: Einführung in die Lehre vom
Denkstil und Denkkollektiv", Frankfurt a. M.: Suhrkamp, 1980. Ludwik Fleck: "Erfahrung und Tatsache: ge-
sammelte Aufsätze", ed.b. Lothar Schäfer, Frankfurt a. M.: Suhrkamp, 1983. Ludvik Fleck: "Denkstile und
Tatsachen: gesammelte Schriften und Zeugnisse", ed.b. Sylvia Werner, Berlin: Suhrkamp, 2011. Edwin
Hutchins: "Cognition in the Wild", Cambridge, Mass.: MIT Press, 1995.
x See Chandra Mukerji: Impossible Engineering: Technology and Territoriality on the Canal du Midi, Princeton:
Princeton University Press, 2010. Eugene Ferguson: Engineering and the Mind’s Eye , Cambridge: MIT Press,
1996.
xi Ian Hacking: "Do we see through a microscope?", in: "Images of Science. Esssays on Realism and
Empiricism", ed.b. Paul M. Churchland, Clifford Hooker, Chicago, 1985. Ian Hacking: "Representing and
Intervening", Cambridge, 1983. Ian Hacking: "Experimentation and Scientific Realism", in: J. Ceplin (Ed.):
"Scientific Realism", Berkeley, 1984.
27
xii Some historians of science did conquer these "murky realms" of creativity – an ironical coining of Daston's
(Daston 2008, p.101): Lissa Roberts/Simon Schaffer/Peter Dear (Eds.): "The Mindful Hand: Inquiry and
Invention from the Late Renaissance to Early Industrialization", Dutch Academy of Sciences, Amsterdam, 2007.
Howard Gruber: “On the Relation of Aha-Experiences and the construction of ideas", History of Science, vol.
19, 1981, pp.41-59. W.B. Carlson/M.E. Gorman: “A cognitive framework to understand technological creativity:
Bell, Edison, and the telephone”. In: R.J. Weber/D.N. Perkins (Eds.): "Inventive minds: Creativity in tech-
nology", Oxford: Oxford University Press, 1992.
xiii Larry Holmes was a master in reading laboratory note books on this matter: "narrowly internalistic" (Holmes
1990, 363), as he once ironically labeled himself. Frederic Lawrence Holmes: "Scientific Writing and scientific
discovery", Isis, vol.78, no.2, 1987. Holmes: “Laboratory Notebooks: Can the Daily Record Illuminate the
Broader Picture?”, Proceedings of the American Philosophical Society, vol.134, no.4, 1990, pp.349-366.
Holmes: “Lavoisier and the Chemistry of Life. An Exploration of Scientific Creativity”, Madison: The
University of Wisconsin Press, 1985. Holmes: "The Fine Structure of Scientific Creativity”, History of Science,
vol.19, 1981, pp.60-70.
xiv Lorraine Daston, Peter Galison: "Objectivity", New York: Zone Books, 2007. Especially chapter four, where
Daston and Galison speak of 'personae' of natural philosophers/scientists in a typological way. Cognitive
practices in this view derived from epistemic virtues in the Kantian sense. Daston has been much more
'psychological' with regard to cognitive practices in: Lorraine Daston: "On Scientific Observation", Isis, vol.99,
no.1, 2008, pp.97-110. See also Lorraine Daston: "The Moral Economy of Science", Osiris, vol.10, 1995, pp.2-
24. Lorraine Daston: "Sweet Reason", Isis, vol.75, no.4, 1984, pp.717-721.
xv Jens Loescher: "'Sincere Hand and Faithful Eye': Cognitive Practices in Ensembles of Text and Drawing",
Gesnerus. Swiss Journal of the History of Medicine and Sciences (submitted).
xvi Swammerdam had the camera obscura at hand and used it.
xvii Of course Hooke spoke of the "sincere hand and the faithful eye". Robert Hooke: ’Micrographia’ or some
physiological descriptions of minute bodies made by magnifying glasses with observations and inquiries
thereupon, London: Martyn/Allestry, 1665. pp.9-10.
xviii Copper plates needed to be printed on a special kind of paper which is why illustrations generated by this
method in contrast to wood cuts are always presented in special sections of a book.