Huygens’s Comments On Spinoza’s Theory of the Microscope to His Brother

[Opening Comment: I post below an extensive excerpt from a significant letter by the hand of Christiaan Huygens. It is has been cited by biographers for two main reasons. For one, the initial sentence is stated as evidence for Huygens’ regard for apparently an argument or demonstration that Spinoza had put to him in Voorburg, one possibly with some conjunction with Johannes Hudde:

“It is true that experience confirms what is said by Spinoza, namely that small objectives in the microscope represent the objects much finer than the large ones.”

What is not mentioned is that this is the first sentence of a letter devoted to its theme of a compromise with Spinoza (and Hudde) over the issue of small lenses and greater magnfication). Far from being a sidenoteof the letter, Huygens has Spinoza’s argument in the forefront of his mind.

What is also considered significant about this letter (and others like it) is the way that Spinoza is addressed. Here, at the end, not by his name, but as being called “the Israelite”, (and elsewhere as “the Jew”). This is meant in the eyes of many interpreters to signify the distance that Huygens kept between himself and Spinoza, implying that he is merely “the Jew” or “the Israelite” in letters. Indeed there were likely uncrossable social status barriers between the two, but the impression left by some that Spinoza was merely “the Israelite” is not deserved, for the very letter opens with his name and his overarching position.

Other than these two much-traveled points, grafted from the letter, and others related to it, what I find most suggestive is that Spinoza’s position seems to be one shared with Johannes Hudde (they are paired at the end of the selection), and Huygens has responded to Spinoza’s point by with a compound microscope construction of a unique design, whose compromise magnification is measured at 30x. This leaves open the question as to whether Spinoza’s argument was for simple or complex microscopes (or both), but gives us a baseline from which to assesss the magnification achieved by Spinoza’s instruments, for they must be significantly greater than 30x. 

For those unfamiliar, Christiaan Huygens, was one of the most incandescent scientific minds of the 17th century (he invented the pendulum clock and discovered the rings of Saturn in the same year!). It is thought that Spinoza and he spent some significant time together in discussion between at least 1664 and the summer of ‘1665, as they were neighbors in the town of Voorburg until Christiaan left for Paris in the summer of ’66. At the time of the writing of this letter Huygens had already become the Secretary to the newly formed Royal Academy of the Sciences of France, and he write to his brother Constantijn Jr., who remained a neighbor to Spinoza. Constantijn was Christiaan’s partner in lens-grinding and instrument making, something that seemed to be a bond between them.

Huygens’ Letter to Constantijn  
Letter No. 1638

Christiaan Huygens à Constantyn Huygens, frère.
A Paris ce 11 Maj 1668

Il est vray que l’experience confirme ce que dit Spinosa que les petits objectifs au microscope representent plus distinctement les objects que les grands, avec des ouventures proportionelles, et sans doute la raison s’en peut donner, quoyque le Sieur Spinosa ni moy ne la scachions pas encore, mais aussi de l’autre costè il est certain qu’on distingue plus de profondeur aux objects quand l’objectif est moins convexe. de forte qu’il faut tenir le milieu entre l’un et l’autre pour avoir des microscopes qui sassent uneffect agreeable, mais si on ne cherche qu’a grosser beaucoup il faut des petites lentilles. I’ay essayè vostre derniere proportion avec vos objectifs et deux oculaires joints l’un contre l’autre qui font un bon effect sinon que les points paroissent trop, et bien plus que lors qu’on n’emploie qu’un oculaire seul de 2 pouces, et la raison y est toute evidente, puis que l’un est de 3 pouces et l’autre de 2 ½. Il vaudroit donc mieux que l’un fut de 4 ou 5 pouces du premier, parse qu’ainsi les points de l’un ni de l’autre ne paroistront pas.

Nostre anciene maniere avoit les deux oculaires si pres de l’oeil que cela empeschoit les points d’estre veus, a quoy contribuoit encore beaucoup l’ouuerture de l’objectif un peu grande. car estant petite et la multiplication forte, il est malaise que les points de l’oculaire pres de l’oeil ne paroissent, et le meilleur remede est de faire d’une matiere qui n’aye que fort peu de points. I’ay dans mon microscope un petit oculaire de 6 lignes, qui est de telle matiere, et aussi blanche que du crystal de roche; avec cela elle est fort bonne et souffe pour le moins aussi grande ouuerture que vostre petite que je vous renvoie. Je retiens l’autre pour faire des essays et vous en remercie. le poly est fort bon.

Voicy les mesure de la vraye Campanine, avec la quelle j’ay estè comparer la miene, qui a cause de la grande ouverture que j’avois donnè a l’objecif estoit beaucoup plus Claire, mais en recompense un peu moins distincte que l’autre, qui en effect est un peu somber, mais, pourtant tres excellente. J’ay du depuis ester cy mon ouverture, mais cela fait paroistre les points des oculaires qui en sont assez chargez.

L’ouverture chez l’Abbè Charles est cellecy. [insert the figure of a circle, approx. 1.25 cm in diameter]

Le diaphragme tel [insert the figure of a circle, perhaps a touch less in diameter]

Du trou de l’oeil au premier oculaire [insert the figure of a line segment, approx. 2.5 cm]
Du premier au second oculaire.
[insert the figure of a line segment, approx. 6.5 cm]
Du second oculaire au troisieme.
[insert the figure of a line segment, approx. 6.75 cm]

Je prens tousjours du milieu de l’epaisseur des verres.
Les 3 oculaires ont chacun leur distance de foier d’ 1 pouce 10 lignes.
L’objectif est de 2 pieds 5 pouces.
Toute la longueur de la lunette 3 pieds 3 pouces, qui est moindre de 4 pouces que la meine. tout est mesure de Rhynlande.
Pour ce qui est de ma nouuelle methode de composer un petit cave avec un objectif, le ne trouve pas qu’il y ait de vos petites formes qui vous puissent servir. mais pour un verre planoconvexe de 2 pieds 8 pouces comme vous en saites, il saut un oculaire don’t l’une des superficies soit travillee dans un creux comme cettuicy [insert figure of a small concave-plano lens] dont le demidiametre soit 289/1000 d’un pouce, et l’autre sur une boule don’t le demidiametre soit 187/1000 d’un pouce, [insert figure of a circle approx. .6 cm in diameter] qui est telle, de forte que vostre lentille creuse sera de cette forme [insert a concave-convex figure, with two small protruding notches near the axis], et il faut tourner le costè convexe vers l’oeil. Cette lunette grossira 30 fois, er pour cela il faut travailler l’objectif un peu grand, a fin de luy donner grande ouverture. Le costè convexe doit estre en dehors. Ce composè, suivant la demonstration, doibt faire autant que les verre hyperboliques, parce que le concave corrige les defauts de l’objectif qui vienent de la figure spherique, c’est pourquoy je ne puis pas determiner l’ouverture de l’objectif qui peut ester pourra ester 3 ou 4 sois plus grande qu’a l’ordinaire, mais si nous la pouvons seulement faire double ce fera beaucoup gaignè et la clartè sera assez grande pour la multiplication de 30. L’oculaire ne doibt avoir qu’une petite ouverture et qui soit prise justement au milieu. Il n’est pas necessaire de vous recommander le secret. et quand mesme l’invention ne reussiroit pas je ne voudrois pas que vous en dissiez rien l’Israelite, a fin que par luy, Hudden ou d’autres ne penetrassent dans cette speculation qui a encore d’autres utilitez.

Pour autheur de dioptrique je n’en vois pas encore de meileur que Kepler, dont il y a un exemplaire dans la bibliotheque de mon Pere, outre celuy que j’ay emportè, qui est reliè avec d’autres traitez. demandez moy ce que vous n’y comprendrez pas, et ce que vous voulez scavoir d’avantage, et je vous esclairci…

 

[I post this letter for two reasons. Firstly, its body should be made easily available to others researching, or even thinking about Spinoza and his place amid 17th century sciences. It is an informed, first-hand response to a theoretical position that Spinoza held. Secondly, and unfortunately, because my French is nearly non-existent, aided by software and careful thought.

It is my hope that someone would be moved so as to accurately translate the text into English (or another language for that matter), which we may be able to post as an effective and accurate on-line source. Perhaps even the donation of a paragraph or so by individuals, so that this would be translated by community would be interesting. My email is kvdi@earthlink.net . 

It should be noted, the measurements of the figures to be inserted are only thumbed approximations meant only for visualization, and not for fact. ]

Constantijn Huygens Uses Spinoza’s Grinding Dish (1687)

In correspondence Wim Klever directs my attention to evidence that the Huygenses used Spinoza’s grinding equipment as late as 10 years after his death. The citation is here, thus translated from the OCCH:

[I] have ground a glass of 42 feet at one side in the dish of Spinoza’s clear and bright in 1 hour, without once taking it from the dish in order to inspect it, so that I had no scratches on that side ” (Oeuvres completes vol. XXII, p. 732, footnote).

If I have the details here correct, it seems either that indeed the Huygenses had purchased Spinoza’s lens grinding equipment at auction in November of 1677 and maintained the use of that equipment, or that Spinoza may have made a grinding-dish for the brothers under their specification before he died. What is revealed is that Spinoza’s skill had been directed toward not only microscope instruments, but also towards telescopes of a rather large magnitude. This lens appears to have a focal length of 42 ft. And secondly of course, here Constantijn jr., a rather experienced lens-grinder himself, seems to have marveled at the confidence in the lumininocity of the lens produced.

(This reported Spinoza lens is much shorter in focal length than three known to have been made in 1686 by Constantijn: w/ diameters 195, 210 and 230 mm, and w/ focal lengths of 122, 170 and 210 ft.; each “made from the same very poor glass – a heterogeneous and discoloured potash-rich, but essentially lead-free `forest glass’.”)

 

Did the Huygenses “buy” Spinoza’s lens polishing technique?

The Meteoric Rise of Huygens’s Microscope

The following is an exercise in historical imagination, only meant to elicit what is possible from what we know. Perhaps a fiction bent towards fact.

Wim Klever has brought to my attention a detail which sheds some light upon the possible lens polishing techniques Spinoza employed. Admittedly the connective tissue for a conclusion is not there, but the inference remains.

Professor Klever tells me that in his “Insignis opticus: Spinoza in de geschiedenis van de optica” he cites Freundenthal’s publication of the advertisement of the auction of the Spinoza’s estate in the Haarlemse Courant. The advertisement was printed on November 2nd, and occurred on November 4th (almost 9 months after Spinoza’s death). It seems likely that Constantijn Huygens jr., and/or his brother the famed scientist Christiaan,  bid at and purchased what remained of Spinoza’s estate. This is how Wim Klever roughly translates some of the items:

books, manuscripts, telescopes (‘verrekyckers, mind the plural!), microscopes (‘vergrootglazen’, also plural), glasses so grinded (‘glazen soo geslepen’), and various instruments for grinding (‘en verscheidene slypgereedschap’) like mills (‘molens’, also plural!) and great and small metal dishes serving for them (‘groote en kleine metale schotels daartoe dienende’) and so on” (en so voort).

It is the number of devices and equipment that is Klever’spoint. Spinoza is not a dabbler in optics. He does not grind a few spectacle glasses for the near-sighted, but rather is interested in full-blown optical instrument production. There are multiple telescopes and microscopes to be had, as well as perhaps something more important, his grinding dishes, and at least two lathes or mills not to mention other small details of his process. Certainly the bill of sale attests to a rather thorough industrial investment on Spinoza’s part, making of his optical enterprises something quite substantial, but what I am most interested in here is the timing of this auction, in the view of the events that immediately are set to follow, events which may give clue to the nature of just what it is that Constantijn Huygens purchased for his brother.

Spinoza’s death, and auction occurs right at the doorstep of a very important moment in history: the official discovery of protozoa, bacteria, and then spermatozoa by Van Leeuwenhoek in nearby Delft. And it is this discovery which will eventually catapult the single lens simple microscope into European renown. But there is, I suggest, a good chance that Spinoza had been making, using, giving to others and possibly selling this kind of microscope for a very long while (Klever translates “vergrootglazen” as “microscope” as one should, but there is another word for microscope, and this word means “glass that magnifies” perhaps more suitable for a single lens microscope.)  

 

First, I should point out that Christiaan Huygens had been a neighbor to Spinoza since 1663 when Spinoza moved to Voorburg, a sleepy village just outside ofThe Hague. He is a profound experimenter and scientist, having, among other remarkably brilliant things, invented the pendulum clock and discovered the rings of Saturn in the very same year of 1656. Spinoza had, most agree, become a conversational friendinthe summer of 1665, when the two of them discussed optical theory it seems with some regularity and detail. The Huygenses lived about a 5 minutes walk from Spinoza’s room at the house of master painter Daniel Tydeman, just down the road. Christiaan moved to Paris in 1666 to take the prestigious position of founding Secretary to Académie Royale des Sciences established by the Sun King Louis XIV to rival the Royal Society of London. There was no doubt extreme pressure to counter and surpass the great flow of knowledge that was collecting at the Royal Society under the supervision of Oldenburg. 

During the intervening years, as Huygens attempted to bolster his Academy, in letters written to his brother back in Voorburg he expressed interest in Spinoza’s lens polishing technique. As early as 1667, he writes Constantijn “the [lenses] that the Jew of Voorburg has in his microscopes [I don’t have the original word here] have an admirable polish” and a month later again, “the Jew of Voorburg finishes his little lenses by means of the instrument and this renders them very excellent”. Here we have an attestation to both the mystery of the quality of Spinoza’s polish, (it was a technique which Spinoza apparently kept to himself); and also there is the hint that the instrument used was meant for very fine work, on the smaller of lenses. (In general, the difficulty in acquiring a fine polish on lenses was a significant aspect of lens-crafting technique, as polishing away the pitting of the glass brought in the grinding often would change the spherical shape of the lens.) In 1668 Christiaan then writes to his brother a concession over a debate that he must have been having with Spinoza, that Spinoza is right that the smallest objective lenses make the very best microscopes.

These references by Christiaan establish that the Huygens brothers’ had interest in techniques which Spinoza was not free with, and that Spinoza was on the side of the debate that theoretically would favor the use of single lens microscopes; this, at the very least, confirms their acquisition of his equipment and lenses to be something of a notable event. If there was anything to Spinoza’s technical capabilities which resided in the equipment he used (small grinding dishes, the nature of his lathe, an abrasive recipe, a polishing material), this fact might be evidenced by a sudden change in the capacities of either brother in making microscope lenses.

And remarkably, such a change was to come.

Now the issue of timing. Here is a timetable of events that led up to Christiaan Huygens presenting a “new microscope” to the Académie Royale des Sciences, one that perhaps reflects something of Spinoza’s technique in crafting lenses.

9 Oct. 1676  Van Leeuwenhoek sends his letter regarding the discovery of protozoa and bacteria.

21 Feb. 1677  Spinoza dies at the The Hague.

22 Feb. 1677  Van Leeuwenhoek’s letter 18 to the Royal Society is read aloud, the “first ever written account of bacteria” (Dobell).

August 1677 Van Leeuwenhoek discovers the animalcules in semen, spermatozoa

4 Nov. 1677 Spinoza’s auction, the Huygenses seem to have acquired some of Spinoza’s equipment.
@ 4 Nov. 1677 Van Leewenhoek writes to the president of the Royal Society, William Brouncker, about his observation of the spermatozoa in semen. This sample was brought to him by Leiden medical student Johan Ham (who also might have had a single lens microscope).
Late 1677 Christiaan expresses interest in the Van Leeuwenhoek/Ham discovery (OCCH 8:77; and 62-3, 65).

March 1678  Hartsoeker explains to Christiaan how he makes lenses from beads of glass.

16 July 1678  Christiaan presents to the Académie Royale des Sciences the “new microscope” that differs from others in Holland and England only in the very small size of the lens.

Aug. 1678  Christiaan writes “my microscopes” have made a “great noise” in Paris.

One must know that single lens microscopes had already been in use in the Netherlands for some time before these dates. It had been used, but its capacity for magnification had not been regularly harnessed to make scientific discovery. Part of this was due to a difficulty in using it, for it must be pressed very closely to the eye, requiring great patience, and lighting techiques for the specimen in contrast had to be developed. And part of this dearth of scientific discovery was due to simply the lack of a conceptual framework for the microscopic world. This was a new world. Few as yet would even know where and why to point such a small and powerful viewing glass. Be that as it may, the microscope technique of forming tiny bead lenses from threads of melted glass was certainly known and talked about in a close scientific circle of experimenting savants (a short history of the spherical glass here). Among those notables were Spinoza’s correspondent Johannes Hudde who made them at least since 1663 when he showed his design to the French diplomat Monconys, and possibly used it as early as 1659 when he youthfully writes in a letter how he will uncover the secrets of generation through its powers. The scholar Vossius has one in 1663 which he also shows to Monconys, and in 1666 publishes the claim that the smaller the lens the stronger the magnification. And then to greatest attention Hooke describes his own bead microscope in the Micrographia in 1665 (some comments here), complaining though that it is too difficult to regularly use, fearing the loss of his eyesight.

 

Hooke's Fly's Eye, from the Micrographia

And of course, it is the king of all microscopists, Van Leeuwenhoek, who exclusively employed this kind of microscope, making over 500 of them almost all for his personal use (some comments here). When he began using them is of much debate. He makes a claim late in life that had had made bead microscopes as early as 1659 (so simple are they to make!), yet some scholars find him to have been directly informed by the description left by Hooke in the Micrographia. We do not hear of his use until 1774, and the nature of his microscope he keeps secret for sometime. It is Van Leeuwenhoek’s microscope – upon the reading of his 18thletterto the Royal Society, the day after Spinoza’s death – that will suddenly take center stage through its discoveries (although its nature at this time remains largely unknown). The single lens microscope is the strongest microscope in the world, but only now will Christiaan Huygens be coming to realize it.

For many years it seems Johannes Hudde had to defend his tiny spherical lenses against Huygens’ intution that larger, compound scopes would do a better job. It seems quite likely that Spinoza found himself mostly on the Hudde side of the argument, even I think it likely that it was Hudde himself, or one in his circle who disseminated the technique to him, either in Amsterdam or at Leiden. To this possibility, the famed Leiden anatomist Swammerdam attributes Van Leeuwenhoek’s technique to Hudde, as he does his own’ and Borch in his diary mentions the heavy influence of Hudde upon these Cartesians. Apart from this debate, Christiaan as a user of the compound scope as late as January 1675 to Oldenburg expresses an outright pessimism towards Van Leeuwenhoek discoveries already relayed to the Royal Society. These may be founded on his own frustrations when attempting to repeat the experiments, as he simply did not have enough magnification power, or they may even be a product of Van Leeuwenhoek’s low social standing as a mere draper in Delft (while Christiaan does not strictly know what kind of microscope Van Leeuwenhoek possesses, he may have guessed. There may be a class issue that folds into the conception of the microscope. Bead lenses are simply, too simple. They are not the shiny, gearing tubes of an upper machinery):

I should greatly like to know how much credice Mr. Leeuwenhoek’s observations obtain among you. He resolves everything into little globules; but for my own part, after vainly trying to see some of the things which he sees, I much misdoubt me whether they be not illusions of his sight…(Dobell 172)

Christiaan Huygens Makes His Turn

But back to the excitment. Something has turned Christiaan Huygens’ pessimism of the simple microscope into an enthusiasm. Most certainly some of this can be attributed to the sudden notability of Van Leeuwenhoek’s discovery of the protozoa and bacteria in marshy and boggy water. In November he will have discovered what male semen looks like under high magnification. At stake were arguments over just how Life itself was generated. (Did it arise spontaneously as it seemed to do in moulds, or was there some “mechanism” to it?) One can imagine the primacy of such a question. Secondly though, it is thought that Christiaan Huygens’s sudden leap towards the simple microscope was nearly entirely triggered and faciliated by the young microscopist Hartsoeker, who not long too before had discovered this technique for himself. The two were in correspondence and in March 1678 Hartsoeker reveals to him his secret. As Edward Ruestow narrates in his wonderful history The Microscope and the Dutch Republic:

The announcement of the discovery of spermatozoa in the fall of 1677 arouses the particular interest of Christiaan Huygens and, through the young Hartsoeker, drew him belatedly to the bead microscope…but having heard of a young man in Rotterdam whose microscopes could reveal the recently discovered spermazoa, Christiaangot in touch with Hartsoeker.

The essential account of their first contact, which is Hartsoeker’s, is tainted by its entanglement with his later claim that he had in fact been the first to discover spermatozoa. The surviving correspondence begins with a reply from Hartsoeker in March 1678 in which he explained how he made the bead with which he observed the “animalcules” found in semen. He presented Christiaan with a number of these sphericals, as well as some wood and brass devices to hold them in place, and by the endofthe month had himself come to The Hague to show Christiaan the spermatozoa of a dog. Hartsoekercontinued to correspond with Christiaan about the employment and improvement of these instruments, all of which Christiaan meanwhile shared with his brother Constantijn. The following year Constantijn spoke of Hartsoeker as “the inventor of our microscopes,” and years later Christiaan recalled Harksoeker having taught them to make little spheres that served as lenses (24-25)

This is all very convincing. Christiaan, after many years of resistance to the idea of tiny spherical lenses, debating with Hudde and possibily Spinoza, spurred on by the need for more powerful magnfication due to the discovery of protozoa, bacteria and then the most importantly, the elusive key to life, spermatozoa, collaborates with a savantish, largely unknown young man from Rotterdam who even claims that had discovered the technique himself when he was a young boy, and suddenly is applying his own rather vast device-making knowledge to craft the best microscopes in Europe, presenting them to the Paris academy, confirming Van Leeuwenhoek’s discoveries only three and a half months after having learned how to bead lenses himself. Huygens is shopping his microscope across the continent, while Van Leeuwenhoek refuses to allow anyone to look into or even see his.

But the problems with this quick reversal narrative is subtle. For one the lens-bead techique is extremely simple. Hartsoeker himself said he discovered it while toying with a thread of glass and a candle. Swarmmerdam says that he could make 40 more or less servicable bead lenses in an hour. It also, as I have said, was rather ubiquitous. To recount: Huddehadbeen in possession of it at least since 1663, was willing to depart with it for at least Swammerdam and Monconys, andin fact had discussed its advantages with Huygens in April 1665. As M. Founeir describes Huygens’ objection to Hudde:

Hudde discussed the merits of these lense with Huygens [OCV, 308-9, 318, 330-1], who declined their use. He particularly deplored their very limited lack of depthof field. He foundit inconvenient that with such a small lens one could not see the upper and underside of an object, a hair for instance, at the same time (“Huygens’ Design…” 579).

Vossius, Huygens’s friend seems to be in possession of it then, and it is no doubt related to the “flea glasses” that Descartes speaks of in 1637, “whose use is quite common everywhere”.  Further, of course, when Hooke describes it in brief in his 1665 Micrographia, he exposes the method to the whole English reading world. This text Huygens remarkably had in his possession very soon after its publication, one of the few copies in Europe despite the Anglo-Dutch war of that year; and we have that copy, a section of which is annotated with Huygens’ hand.  Huygens had even been so kind to actually translate some of the English for Johannes Hudde.

Further in evidence that Christiaan Huygens was well-familliar with this lens, in November 1673 Hooke demonstrates to the Royal Society “microscope with only one globule of glass, fastened to an instrument with many joints” likely made in wide production by the Dutch instrument maker Musschenbroek. And even more conclusively, Christiaan’s own father Constantijn Sr. a few months later writes of a powerful “machine microscopique” used by both Swammerdam and Leiden professor of Botany Arnold Seyn (Ruestow, 24 n.96); and we know that Swammerdam later favored a single lens scope. Given their prevalence, simplicity andthe extent of Huygens’ likely intercourse with these lenses, it could not be that Christiaan Huygens and his brother were somehow deprived, waiting to be told how to bead glass by the 22 year old [Leiden student?] Hartsoeker? It may be imagined that perhaps Hudde kept his personal means of grinding tiny lenses secret from Huygens due to some competitive antagonism and Huygens’ obstinancyover the larger, compoundlens microscope design. Perhaps. But it could not be that all of educated Europe keep it a secret from one of the foremost scientific minds of the time. Something does not sit right. Was it simply Huygens’s disinterest in such a low-depth of field, simple lens, andhis proclivities for certain other types of lens formations (compound, like his telescopes) that kept him from wanting to know? Was Hartsoeker simply the expedient when Christiaan needed to catch up quickly? The way that Edward Ruestow tells it we get the sense that it merely took the interest of Huygens, the timely injection of technique, and then the application of the Huygens’ brothers marvelous technical sense. Perhaps.

But I suggest that one piece is missing from this puzzle. It may be not until the Huygenses acquired the lens-grinding equipment and lens examples from Spinoza’s estate that they possessed the technical means of polishing these small spherical bead lenses: a talent for minute polish which Spinoza had showed early on. Could it be that this was the link, the technical means which accelerated the rapid development of the Huygens microscope from concept to actuality?

The Huygens droplet design, as it ended up in late 1678

Ruestow cites the kinds of changes that the Huygens brothers made to the Hartsoeker lens technique, such as “removing the molten globule from the thread of glass withametal wire, or, with one end of the wire moistened, picking up small fragments of glass to fuse them into globules over the flame” (25). All these seem aimed trying to make the sphere smaller and smaller, increasing its magnification. In the endChristiaan would proclaim to his French audience that his microscope is not much different than those in Holland and England, other than the size of its smaller lens, supposedly something which he alone had achieved.

He also produced a casing that was built around this tiny lens, “mounting their own beads in small squares of thin, folded brass; with the bead trapped between the opposing holes pierced with a needle through the two sides of the folded brass, those sides were pinched together with hammered pieces of wire. The microscope would go through several revisions.

As Ruestow writes of its appearance in Paris:

“on July 16th he presented to the assembly the ‘new microscope’ he had brought back withhim from Holland – one that, according the the academy minutes, was ‘extraordinarily small like a grain of sand’ and magnified incredibly…before July was out, Christiaanusedthe instrument to show the members of the academy the microscopic life Leeuwenhoek had found in pepper water, soon after publishing the first public announcement of their discovery in the Journal des Sçavans, Christiaanalsoidentified it with the discovery of the spermatozoa.” 

By August his microscope had caused the “great noise” all over Paris, so much so that John Locke at Blois had heard of it. Through the next year he had “cultivated the impression” that Van Leeuwenhoek’s observations were made with a microscope like his own. French instrument makers set to copying his invention. The response was not altogether gleeful. In London Hooke was somewhat put out that so much excitment surrounded what for him was a well-known device, one that he himself had fashioned, used and written of. And Hartsoeker, having finished his third year at the University at Leiden, all the while had been left in the shadows, not something that sat well with his rather conceitful temperment. Traveling to Paris Hartsoeker sought in some way to unmask his role in the creation of this remarkable device, exposing Huygens to be something of a plagerist. As Ruestow reports, knowing wisely Christiaan steered him from that course,

but [Christiaan] quickly took his younger compatriot under tow and wrote a brief report for him, published in the influential Journal des Sçavans, that asserted Hartsoeker’s active role in making new bead microscopes (27).

We have here evidence of Christiaan’s tendency to obscure the origins of his microscope. Yet was there more to the development than simply Hartsoeker’s revelation of the thread melting techique? Was it that in the purchase of Spinoza’s lens-polishing equipment they acquired something of the techiques long appreciated by the brothers? Does this technique prove essential to Christiaan’s implementation of a rather simple bead-glass lense? Was Hartsoekersimply solicited for the one remaining aspect of the technique that Spinoza’s equipment would not provide, that of simply melting the glass into a lens? We do know that the grinding of the already quite spherical bead was common among its users. For instance Van Leeuwenhoek ground and polished almost all of his tiny bead lenses, (and modern assayers do not quite know why). Further, Johannes Huddealsopolished his bead lenses, reportedly with salt. Was there something to Spinoza’s knowledge of small lens-crafting that facilitated Huygens’ suddenly powerful microscope design? Something even that Hartsoeker was privy to? And lastly, if Spinoza’s equipment and techniques are implimented in this sudden rise of the simple microscope, what does this say about Spinoza’s own microscope making practices.

All this fantastic story is just speculation of course

It could merely be a coincidence that, with Spinoza having died just as protozoa and bacteria were being discovered; and with his equipment coming into the hands of the brilliant Huygenses almost 9 months later, they they then just happen to be aided by a young microscopist that gives the means needed to suddenly develop a microscope that will sweep across Europe in merely a few months. Christiaan Huygens and his brother were brilliant enough for that. Perhaps Spinoza’s ginding dishes and recipes simply sat in the dust, having been acquired. But it should be noted that many years before this, the physcian Theodor Kerckring, a friend of Spinoza’s and a member of the inner, Cartesian circle, son-in-law to its central member Franciscus Van den Enden, writes of his use of Spinoza’s microscope:

“I have to my disposal a very excellent (praestantissimum) microscope, which is fabricated by that noble Benedictus Spinosa, mathematician andphilosopher…What I in this way discovered with the help of this admirable instrument…[are] endless many extremely small animalcula….”

This is found in his Spicilegium anatomicum published in 1670, seven years before Van Leeuwenhoek’s acclaimed description of the protozoa and bacteria in letter 18. It is not clear at all what “animalcula” Kerckring saw (some offer that they are post-mortum microbes, or mistaken ciliated action), but there is the possibility that these were the earliest microorganisms to be described, or at the very least, Spinoza had perfected an advanced form of the single lens, bead-microscope whose powers of magnfication approached many of those of Van Leeuwenhoek, and even that of its copist Christiaan Huygens. The timing remains. In November of 1677 the Huygenses lmay have acquired Spinoza’s lens grinding equipment, and in 8 months they have a microscope of remarkable powers.

Descartes and Spinoza: Craft and Reason and The Hand of De Beaune

Some Reflections on Letter 32

Descartes in 1640 reports to Constantijn Huygens, “You might think that I am saddened by this, but in fact I am proud that the hands of the best craftsman do not extend as far as my reasoning” (trans. Gaukroger). And as Graham Burnett translates, “Do you think I am sad? I swear to you that on the contrary, I discern, in the very failure of the hands of the best workers, just how far my reasoning has reached” (Descartes and the Hyperbolic Quest, 70).

The occasion is the wounding of the young, brilliant craftsman Florimond De Beaune on a sharp piece of glass, as he was working to accomplish the automated grinding of a lens in a hyperbolic shape on a machine approximating Descartes’ design from La Dioptrique. This at the behest of Descartes himself:

His wound to the hand was so severe that nearly a year later De Beaune could not continue with the project, a project he would not take up again. Descartes’ craftsmanless, all-turning machine could not be achieved. It is as if its “reason” had chewed up even the best of earth’s craftsman.

Compare this to Spinoza’s comment on Christiaan Huygen’s own semi-automated machine, in letter 32 to Oldenburg. (One wonders if he may even had had a now infamous injury to De Beaune in mind.) Descartes seems to write callously to Christiaan’s father in 1640 [following Gaukroger’s citation], 25 years later Spinoza writes soberly about the machine of the son:

…what tho’ thusly he will have accomplished I don’t know, nor, to admit a truth, strongly do I desire to know. For me, as is said, experience has taught that with spherical pans, being polished by a free hand is more sure [tutius] and better than any machine.

Issues of class play heavily into any attempt to synthesize the rationality of a mechanism with the physical hands [and technical expertise] of the required craftsman to build it. What comes to mind for me is the same Constantijn’s Huygens enthused reaction to the baseness of the youths Rembrandt and Lievens in 1629, when he discovered their genius. As Charles Mee relates and quotes:

Unable to have Rubens, Huygens evidently decided to make his own Rubens, and he saw the raw material in Leivens and Rembrandt. He loved the fact that this “noble pair of Leiden youths” came from such lowly parentage (a rich miller was still a miller after all): “no stronger argument can be given against nobility being a matter of blood” (Huygens himself had no noble blood). And the fact of their birth made the two young men all the more claylike, so much more likely to be shaped by a skilled hand. “When I look at the teachers these boys had, I discover that these men are barely above the good repute of common people. They were the sort that were available for a low fee; namely with the slender means of their parents” (Rembrandt’s Portrait ). 

The standing of the rising Regent riche had to position itself between any essentialist noble quality of blood, and the now stirring lower merchant and artisan classes, whose currencied freedoms in trade and mobility were testing ideological Calvinist limits. Leveraging itself as best it could on rational and natural philosophy, a philosopher-scientist-statesman was pursuing a stake in freedom and power, one that rested on the accuracy of his products. In this way it seems that Descartes’ – feigned? – glee over De Beaune’s injury, insofar as it embodied a superhuman outstripping of remedial others, manifests this political distancing to a sure degree. De Beaune was no ignorant worker, for his high knowledge of mathematics made him much more “technician” than craftsman, (in fact de Beaune had proposed the mathematical problem of inverse tangents which Descartes would not be clear on how to solve (letter, Feb 20 1639), and it was his Notes brièves and algebraic essays which would make Latin editions of Descartes Géométrie much more understandable to readers). Reason and rationality could in the abstract certainly in some sense free even the most economically and culturally base kinds (at least those with a disposition to genius), but in fact savants likely imagined that their lone feats of Reason actually distanced themselves from the “hands and limbs” on which they often relied.

Seen in this way, Spinoza’s sober view of Christiaan Huygens machine perhaps embodies something more than a pessimism of design, but rather more is a reading of the very process of liberation which technological development represented for a class of thinkers such as Leibniz or the Huygenses. The liberation of accuracy and clarity was indeed a cherished path, but perhaps because Spinoza was a Jewish merchant’s son, excommunicated, because Spinoza understood personally the position of an elite [his father had standing], within a community itself ostracized though growing with wealth, a double bind which he relinquished purposively, any clarity was necessarily a clarity which connected and liberated all that it touched. It was inconceivable to have dreamed a rationality so clear that it would distance itself from the the hands that were to manifest it. Perhaps Spinoza keeps in his mind the hand of De Beaune.