Wrote Letter 51 of 1686-06-10 (AB 93) to Members of the Royal Society about seeds of cotton, kapok, Bupariti, and coconuts, the reproduction of shrimp and lobster, and the eggs of shell fish

Date:

June 10, 1686

Standard reference information

Cole's number:

AB/CL number:

AB/CL volume:

Text of the letter in the original Dutch and in English translation from Alle de Brieven. The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren.

The original manuscript on twelve quarto pages, written by a copyist and signed by Leeuwenhoek, is preserved at the Royal Society (MS. 1913. L 2. 4.).

Leeuwenhoek's summary

From both editions of Cinnaber Naturalis and translated into Latin for all of the editions, some re-titled, of Anatomia Seu Interiora Rerum.

Ontledingen en Ontdekkingen, van het Karpok, Bupariti, Kaukin, ende Adamboe-Zaad, ende het begin van de Plant in the Cocos-Noot; van de Kuyt of Eyeren van de Garnaad, Kreeft, en Krabbe, ende van de ongeboorne Garnaad en Kreeft, ende derselver Voorttelinge, ende die overgebragt tot de Voorttelinge van de Zaden van eenige Boomen.

Dissections and discoveries of the capoc, Bupariti, "Kaukin", and Adamboe seed, and the beginning of the plant in the coconut; of the roe or eggs of shrimp, lobster, and crab and of unborn shrimp and lobster, and the reproduction of the same, and of the carry over to the reproduction of the seeds of some trees.

Kapok is also spelled capoc and is also called the silk cotton tree. According to Alle de Brieven / Collected Letters, Leeuwenhoek was mistaken calling his specimens Kaukin and Adamboe.

Reception in London

In the months after it was written, this letter was read in London in two parts at two meetings, the first on June 30/July 7 (O.S./N.S. Birch's History, vol. IV p. 492, 494):

Part of a letter of Mr. Leeuwenhoeck was read, containing his microscopical observations upon the seeds of several Indian plants, shewing how the leaves and the part designed for the root and stem are wrapped up within the said seeds.

Two weeks later, they heard the last part of the letter.

An account of the manner of the propagation of shrimps, in whose eggs the embryo is perfectly formed before exclusion, after the same manner as some sorts of seeds, which contain the whole plants, being part of a letter of Mr. Leeuwenhoeck, was read.

At the end of this letter, Leeuwenhoek concluded:

After the aforementioned observations I do not doubt but that Your Honours will now feel satisfied on this matter, namely, that there exist several Seeds that have nothing else inside them but the beginning of a young plant.

In both March and May preceding this letter, Leeuwenhoek received letters from Edmond Halley, newly elected clerk of the Royal Society and the editor of Philosophical Transactions.

In the second of those cordial letters, dated May 15, Halley wrote that Leeuwenhoek would be receiving a gift from the Royal Society delivered in person by Mr. Colson, about whom nothing else is known. He also had a request:

Several Gentlemen of the Society, who are your admirers, have heard that yr Picture is of late curiously graved have ordered me to desire of you some few prints to adorn their studies, and one for the Societies meeting room, where you will be sure to be in good company, which you shall think fit to send.

In both the opening paragraph and a short postscript, Leeuwenhoek mentioned Colson, his gift, and the portraits that Halley requested.

I have duly received Your Honours' very agreeable letter of 15/25 May, which served only to accompany the token of honour sent me by Your Honours through Mr. Colson.

In that same Missive Your Honours say, among other things: that this token of honour is merely a sign of respect and gratitude for my constant labours. For this generous and undeserved gift of such a beautiful book I am and remain very greatly obliged.

It was, in fact, Willugby's History of Fishes. Leeuwenhoek doesn't mention it by name or later ever indicate that he had read it. However, he wrote this letter only a couple of weeks after the Royal Society decided to send it to him. He was more impressed with how the Royal Society treated the portrait that he sent to them.

I send you herewith some more of my modest observations and arguments, which, I presume to hope, will please Your Honours: Together with a few illustrations; and if ever I should have thought that such a great honour would fall to my lot to have my portrait hung, in the room where the Friends meet, side by side with other ones, I should not have failed to send it; and I must say once again that I feel very greatly obliged to have received from Your Honours so many marks of honour, and I only wish that I had the capabilities to deserve these.

Leeuwenhoek used the word contrefeitsel, which Alle de Brieven / Collected Letters translates as "pictures" but at the time referred specificially to portraits. If Leeuwenhoek sent twelve, they were not oils. Leeuwenhoek must have referred to the mezzotint (right), a newly developed technique that Johannes Verkolje used to make a reverse image of his oil painting and that could be printed in large quantities from the engraved plate. The verse underneath was composed by Constantijn Huygens, who died the following year.

The mezzotint is dated 1686 and Halley had heard of it by May, so it was probably finished in early 1686. Leeuwenhoek would have sat for the original portrait some time in late 1685. Note the gall nuts on the oak leaves in the lower right, specimens discussed in Letter 50 of May 14, 1686.

Halley had also asked, referring to Mr. Colson:

... the Gentleman that has undertaken to deliver it you, is a very knowing & curious person, & ye Society would esteem it an obligation, if you should think fit to let him view in your most incomparable microscope some of those many curiosities, wherewith from time to time you entertain us, so much to our satisfaction.

It was just a year earlier that Halley had dispatched Thomas Molyneaux from Leiden to Delft on a similar mission to look through Leeuwenhoek's lenses, and that had not gone well. Leeuwenhoek does not say whether Mr. Colson was similarly treated.

Specimens and methods

The first part of this letter described Leeuwenhoek's observations of kapok seeds from India. Always looking for similarities, he wanted to compare whether cotton to capok were "of the same Nature and structure." He also looked at other similar Asian seeds, Bupariti, Kaukin, Adamboë, and the largest that he knew of, coconut.

After presenting all this information, Leeuwenhoek concluded:

In the second part of the letter, he turned to the eggs of shrimp, lobster and crab as well as the embryos in the eggs of shrimp and lobster. The Calculation below showed how small the crab's eggs were.

Concluding this section, Leeuwenhoek invoked one of his principles:

For that reason Provident Nature has been so orderly in all her workings that she never makes a thing in vain

A few pages later, the noted another principle: repetition of observations

Once I had seen [more than a hundred million tiny animals], I have not contented myself with it, but have repeated these observations many times in succession, taking new moisture from the eggs each time, and invariably getting the same result.

In the third part of the letter, Leeuwenhoek compared the propagation of these animals and that of trees. In keeping with his ideas about Provident Nature's Calvinistic foresight, he wanted to show how it solved problems the same way for all of life.

Response to other researchers

Where did the seeds come from?

At the beginning of this letter, Leeuwenhoek returned to Letter 47 of October 12, 1685 (AB 88) to Members of the Royal Society, recounting his observations of cotton seeds:

Since that time, I have visited the Most learned and very Experienced Gentleman Paulus Hermans, Dr. of Philosophy and Medicine, Professor of Botany at the University of Leyden, who paid me such respects, and had so much kindness for me, that he threw open his exceedingly great Seed cabinet for me, adding that I might take from the same those Seeds which I might like.

Well, I had a fancy to examine the Kapok Seed, called in the Hort: Malab: Vol. 3, page 59 Panjala, Sive Arbor Lanigera Bontii; because it also lies in its wool, as does the Cotton seed, this led me to presume that it would also be of the same Nature and structure.

So, having obtained this seed besides other Indian Seeds, by the favour of this Most Learned Gentleman, I proceeded to make my observations upon it: which I could not refrain from communicating to Your Honours, in order to inform you further concerning these Seeds which carry nothing in themselves but the beginning of the plant.

Paul Hermann (1646-1695) (Wikipedia en | nl), who gave Leeuwenhoek the seeds, was a German-born physician and botanist. From 1680 until his death, he was director of the Hortus Botanicus in Leiden. When Leeuwenhoek visited him in 1686, Hermann was preparing Horti Academici Lugduno-Batavi Catalogus, his comprehensive catalog of the Hortus' plants. It would be published in Leiden by Cornelis Boutesteyn in 1687.

Boutesteyn's shop was across the Rapenburg gracht from the Hortus. Since Boutesteyn had published half a dozen volumes of Leeuwenhoek's letters in 1685 and 1686, Leeuwenhoek may well have been in Leiden working on those editions when he made his trek across the gracht to the Hortus.

The public and their opinions

"Those who still, through prejudice, embrace the stupid and fanciful propositions"

Leeuwenhoek ended this long letter with one final point:

To sum up, we can see that the reproduction, both of the quadrupeds, birds, fishes, and of the plants, and the way it works, is brought about in very nearly the same manner; only with this difference, that the trees and plants cannot mate, and therefore the tree, in its reproduction, must bring about alone, that which the male and female sexes of animals, birds and fishes do together.

Putting aside what we know now, that trees and plants do indeed "mate", Leeuwenhoek the empiricist had no other choice but to accept the conclusions that his reasoning from the indisputable visual evidence led him to. That was not true of all the people he knew. He concluded:

Animals come forth only from the little animals of the male Seeds, and that the wombs of the female animals have been made only to receive the male little animals and make them grow

I well know that I have used these or similar words many times: but since not all of those who come to read this (letter) may have seen or heard my previous observations and assertions about the reproduction I consider that I cannot say it too often.

For one thing, in order to strengthen in their opinion those who take my statements about reproduction to be right and true (and have the courage to say that they do not know how anyone can contradict me in these things).

And for another thing, in order to convince those who still, through prejudice, embrace the stupid and fanciful propositions about a nest of eggs (the ovarium) and to bring them to better knowledge.

Calculations

How small is a crab's egg?

Leeuwenhoek was aware of the estimates and assumptions upon which his calculations were based. He was also aware of the commonsense rejection of the results of his calculations. The little aminals were too small and too numerous.

As a result, he was always careful to minimize the measurements. Even so, they were incredible.

And in order to bring before Your Honours' eyes how small are the eggs of this crab, and the great multitude of the same, I have laid a number of eggs side by side upon a subdivided foot-measure, and seen that the axis of 14 eggs amounts to one-sixth the length of an inch. This roe, or eggs, which are very neatly suspended on the vessels in the form of a chain, were together of a size which, when I brought the same together in a ball, this had an axis of very nearly two and a half inches' length.

But I will (as is ever my way) remain on the least side, and say, the axis is only two inches long, and that instead of having to say, the axis of 84 eggs amounts to one inch in length, I will take the number of 80 axes, and say that the axis of the ball-shaped body consisting of the crab's eggs is 2 inches long, and therefore 160 eggs' axes long; this being so, the number that results will be 4,096,000.

He wrote out the multiplication.

Now let us reject half of this number, for one thing because the eggs are not pressed firmly together, and for another thing because the vessels that nourish the eggs take up an ample space; then there will still remain more than two million eggs that a large crab carries about with itself. Or else, if I say that the axis of a walnut is one inch, then the walnut is more than five hundred thousand times larger than a crab's egg.

Visitors to his house

Leeuwenhoek concluded this letter

P.S.
Mr. Colson spent little time at my house, because he and other company were on the point of departing for The Hague, Amsterdam, and Utrecht; and when he comes back again he will come to visit me, when I will hand him twelve portraits to take with him.

Figures

The original drawings are preserved in the Royal Society's archives. The scans on the sidebars came from Opera Omnia, the 1722 fourth edition of Arcana Naturae Microscopiorum.

As seen on the left sidebar, two figures were labeled Fig. 6. In the text, Leeuwenhoek discussed them as one: "Fig. 6. is also the young plant, whose leaves have not been stretched out so much." Alle de Brieven / Collected Letters concluded "There should have been 24 figures."

In the text, Leeuwenhoek noted that someone else drew all of the figures. For example, at the beginning of the letter, he write about where he got the seeds he examined:

To this end I have caused two such exceptional Seeds to be drawn.

Of Fig. 10, he wrote, "This, too, has been drawn through a weak magnifying glass." A few pages later:

Fig: 12 and 13. is the pip or kernel of the Seed, which I have split open and separated into two parts, and had these drawn as large as seen with the naked eye. ... fig: 21, which I also had drawn, as large as the same appears to us in our naked eye.

Finally, when discussing the final two figures, of unborn shrimp, Leeuwenhoek wrote:

In order to place before Your Honours' eyes the makings of an unborn shrimp, I have taken several of the same from the eggs, and placed four of these before my microscope, and had a draughtsman (teijkenaar) come to my house, and instructed the same to follow the figure, as it appeared to him, as closely as possible, without my wanting to tell him what it was that he was drawing; the same said many a time, while he was drawing: I don't know what I am drawing, but it seems to me that it is a shrimp.

Publication history

Related sources, especially Philosophical Transactions, and first editions only of Leeuwenhoek's volumes of letters. For later editions see Related events under Learn more.

Year	Author	Title
1686	Leeuwenhoek, A. van	Cinnaber Naturalis
1687	Leeuwenhoek, A. van	Anatomia Seu Interiora Rerum
1961	Leeuwenhoek, A. van	Alle de Brieven. The Collected Letters. Volume 6

Other publications:

By the time the Royal Society received this letter, Edmond Halley was editor of Philosophical Transactions. This letter was never published there. Nor was it published anywhere else before 1800.

Learn more

Period 4 - 1694-1702

Period 2 - 1679-1686

Structure of the letters in Period 2

1686: Royal Society

Related people:

Members of the Royal Society

Related events:

Date	Event
January 1, 1686	Published Cinnaber Naturalis (Natural Cinnabar), Letters 48 - 52
May 25, 1686	Edmond Halley wrote a letter to Leeuwenhoek about a gift from the Royal Society and requesting some portraits
May 29, 1686	The Royal Society decided to send a gift to Leeuwenhoek
July 10, 1686	The Royal Society read part of Letter 51 of 1686-06-10 about how the leaves, root, and stem are wrapped up with the seeds
January 1, 1687	Published Anatomia Seu Interiora Rerum (Interior Anatomy), 19 Letters from 28 - 52
January 1, 1696	Published Arcana Naturae Microscopiorum (Nature's Mcroscopical Mysteries), 19 Letters from 28 - 52 (2nd)
January 1, 1708	Published Arcana Naturae Microscopiorum (Nature's Mcroscopical Mysteries), 19 Letters from 28 - 52 (3rd)
January 1, 1713	Published Cinnaber Naturalis (Natural Cinnabar), Letters 48 - 52 (2nd)
January 1, 1722	Published Opera Omnia, seu Arcana Naturae Microscopiorum (The Works, or Nature's Microscopical Mysteries), 25 Letters from 28 - 60 (4th)

Top Menu - main site navigation

Letter 51 Figures 1-12

Wrote Letter 51 of 1686-06-10 (AB 93) to Members of the Royal Society about seeds of cotton, kapok, Bupariti, and coconuts, the reproduction of shrimp and lobster, and the eggs of shell fish

Where did the seeds come from?

"Those who still, through prejudice, embrace the stupid and fanciful propositions"

How small is a crab's egg?

Figures

Letters

Letter written to

Letter 51 Figures 13-23