Who wrote letters to Leeuwenhoek?

Of the no doubt thousands of letters Leeuwenhoek received over his adult life, very few have survived. Most of them are from officers of the Royal Society; copies are in its Letter Books Original and Early Letters archives. Some letters by Huygens, Heinsius, and Leibniz are preserved in Dutch and German archives. The letter by Bidloo was published at the time. Many of the letters, for example, those by Rabus, are available at the ePistolarium. Letters from Magliabechi are known from excerpts in Rabus's Boekzaal van Europe.

However, most of the letters to Leeuwenhoek are known only by reference in other letters or other sources.

The letters to Leeuwenhoek are listed chronologically under What happened? below. On the list here, alphabetical by sender's last name, the dates for letters from England are expressed in New Style, which was 10 days (before 1700) and 11 days (after 1700) ahead of the Old Style dates used in England. Including both letters to and from those correspondents shows the extent and sequence of the exchange of letters.

Johan Arnoldi

late Dec 1697 - 15 Jan 1698 to Arnoldi
15 January 1698 from
February 1698 to
April 1698 from
April 1698 to
February 1699 from
February 1699 to

Adriaen van Assendelft

25 March 1713 to
4 November 1714 to

Francis Aston

26 February 1683 from
9 March 1683 to
27 March 1683 from
27 August 1683 from
17 September 1683 to
11 October 1683 from
26 October 1683 to
28 Decemer 1683 to
7 March 1684 from
14 April 1684 to
7 June 1684 from
August-mid-October 1684 from
20 January 1685 from
19 February 1685 from
27 June 1685 from
between 23 July and 22 October 1685 from

Victor van Beughem

May 1697 to

Govert Bidloo

19 January 1698 to
21 March 1698 from
7 March 1706 to
12 March 1706 from

Ewout van Bleyswyck

6 May 1717 to

Hendrik van Bleyswijk

28 December 1695 to
29 August 1696 to
27 September 1696 to
20 May 1700 to
9 February 1702 to

Herman Boerhaave

28 September 1716 to
4 November 1716 from
10 October 1716 from
5 November 1716 to
21 November 1716 to
26 August 1717 to

Robert Boyle

28 July 1676 to
1677 to
1678 to
6 August 1687 to
1688 to
12 January 1689 to

William Brouncker

16 October 1677 to
November 1677 to
2 December 1677 to

Siewert Centen

7 February 1704 from
mid-February 1704 to
late February - early March 1704 from

John Chamberlayne

24 April 1701 from
21 June 1701 to
12 September 1702 from
8 December 1702 to
3 October 1704 to
2 December 1704 from
3 March 1705 to
31 March 1707 from
17 May 1707 to
10 September 1709 to
22 November 1709 to

Charles VI, Holy Roman Emperor

8 December 1717 to

Antoni Cinck

24 October 1713 to
26 March 1715 to
2 July 1715 from
7 July 1715 to
24 May 1716 from Cinck, Narez, Rega
12 June 1716 to
6 July 1717 to

Francesco Cornaro

November 1705 from
18 December 1705 to
28 November 1718 to

Theodore Craanen

1676 to
1677 from

Daniel Gaesbeeck

1 January 1684 from
24 July 1684 from

Thomas Gale

16 March 1680 from
13 May 1680 to
14 June 1680 to
28 September 1680 to
12 March 1686 from

George Garden

3 September 1693 from

Luca Giamberti

July 1697 to
19 July 1697 from

David Gregory

17 July 1681 from

Nehemiah Grew

12 January 1678 from
18 March 1678 to
20 April 1678 from
31 May 1678 to
27 September 1678 to
13 October 1678 from
21 February 1679 to
25 April 1679 to
13 June 1679 to

Jacob Gronovius

11 July 1686 from

Benedictus Haan

28 February 1694 from

Edmond Halley

12 March 1686 from
25 May 1686 from

John Harwood

17 May 1697 from

Anthonie Heinsius

20 May 1683 to
7 June 1683 from
22 July 1683 to
2 September 1683 to
10 September 1683 from
16 September 1683 to
30 September 1683 to
8 October 1683 from
14 October 1683 to
3 August 1685 from
10 August 1685 to
31 August 1685 from
1685-1715 20 letters to
28 February 1715 from
25 February 1716 to

Karl von Hessen-Kassel

after 6 October 1685 from
20 April 1702 to
20 April 1702 to

Robert Hooke

14 January 1678 to
11 February 1678 from
28 April 1678 from
August 1679 from
13 October 1679 to
27 October 1679 from
20 November 1679 to
12 January 1680 to
16 January 1680 to
2 February 1680 from
13 February 1680 to
5 April 1680 to
22 April 1680 from
13 May 1680 to
14 June 1680 to
9 August 1680 to
12 November 1680 to
4 July 1681 from
4 November 1681 to
December 1681 from
3 March 1682 to
20 March 1682 from
26 March 1682 from
4 April 1682 to
28 July 1682 to
9 June 1698 from
11 January 1678 from

Pieter Hotton

September 1704 from Hotton
September 1704 to

Christiaan Huygens

15 February 1677 to
15 May 1679 to
6 March 1689 from
October 1689 to
6 March 1690 from
20 October 1692 from

Constantijn Huygens

February 1674 from
5 April 1674 to
11 April 1674 from
24 April 1674 to
26 December 1674 to
7 November 1676 to
8 December 1677 from
23 December 1678 from
26 December 1678 to
27 April 1679 to
4 May 1679 from
20 May 1679 to
17 December 1685 from

James II, King of England

1 March 1687 to

James Jurin

5 March 1722 from
1 May 1722 to
26 May 1722 from
13 June 1722 to
7 July 1722 to
12 October 1722 from
20 November 1722 to
4 January 1723 from
19 March 1723 to
6 July 1723 from
August 1723 to
August 1723 to

Jan Gerard Kerkherdere

22 June 1716 to
13 July 1717 to

Jan van Leeuwen

18 August 1697 from
3 September 1697 to

Gottfried Leibniz

1696 from
1696 to
1715 to
5 August 1715 from
28 September 1715 to
29 October 1715 from
18 November 1715 to
18 November 1715 to
1716 to
3 March 1716 to
31 March 1716 from
19 May 1716 to
25 September 1716 from
17 November 1716 to

Gerard van Loon

October 1713 from
16 May 1716 to

Antonio Magliabechi

16 March 1686 from
12 April 1686 to
10 September 1686 to
30 October 1686 to
1689 to
27 May 1691 from
18 September 1691 to
24 June 1692 from
before 2 March 1694 from
1695 to
16 August 1695 to
12 October 1695 from
14 October 1695 from
18 October 1695 to
23 October 1695 from
31 October 1695 to
5 November 1695 from
22 December 1695 to
6 March 1696 from
5 June 1696 from
8 July 1696 from
28 August 1696 to
7 September 1696 to
18 December 1696 from
Feb-May 1697 from
1 June 1697 from
6 June 1697 to
August 1697 from
2 November 1697 to
1698 from
20 February 1698 to
March 1698 from
17 April 1698 to
June 1698 from
14 August 1698 to
late 1698 from
28 February 1699 to
8 September 1699 from
16 October 1699 to
1701 from
early 1705 from
12 March 1705 to
10 July 1708 from

Mary, Queen of Great Britain

23 September 1692 to

Jan Meerman

a few years before 1713 to
28 February 1713 to
14 March 1713 to

Isaac Newton

9 November 1714 to

Henry Oldenburg

28 April 1673 to
15 August 1673 to
8 November 1673 to
7 April 1674 to
16 April 1674 to
4 May 1674 from
1 June 1674 to
6 July 1674 to
30 August 1674 from
7 September 1674 to
7 September 1674 to
19 October 1674 to
5 November 1674 from
4 December 1674 to
3 January 1675 from
22 January 1675 to
11 February 1675 to
1 March 1675 from
26 March 1675 to
22 April 1675 from
14 August 1675 to
22 August 1675 from
20 December 1675 to
7 January 1676 from
22 January 1676 to
13 February 1676 from
20 February 1676 from
22 February 1676 to
21 April 1676 to
14 May 1676 from
29 May 1676 to
28 July 1676 to
9 October 1676 to
18 October 1676 from
26 October 1676 from
30 October 1676 to
12 November 1676 from
27 November 1676 to
22 February 1677 from
4 March 1677 from
23 March 1677 to
20 April 1677 from
14 May 1677 to
7 August 1677 from
5 October 1677 to

Daniël Papenbroek

10 September 1686 to

James Petiver

13 August 1711 from
18 August 1711 to

Johann Wilhelm von Pfalz-Neuburg

18 September 1695 to
3 November 1695 to

Hubert Kornelis Poot

10 May 1716 to

Peter Rabus

18 August 1693 from
27 October 1693 to
30 November 1694 to
May 1695 from
21 May 1695 to
between June and 21 July 1695 from
21 July 1695 to
10 September 1695 to
16 May 1696 from
1 June 1696 to
23 July 1696 to
30 July 1696 from

Frederik Adriaan van Reede van Renswoude

22 April 1695 to van Reede van Renswoude
May 1695 from
18 May 1695 to
June 1695 from
10 July 1695 to
15 August 1695 to
20 August 1695 to
December 1695 to
20 February 1696 to
16 July 1696 to
23 August 1696 from
26 August 1696 to
2 June 1700 to
9 February 1701 to
26 August 1701 to
some years before 1716 to
10 September 1717 to

Royal Society from (probable writer)

24 February 1687 (Edmond Halley)
17 February 1696 (Hans Sloane)
10 November 1705 (Hans Sloane)
3 June 1707 (Hans Sloane or John Chamberlayne)
4 November 1707 (Hans Sloane or John Chamberlayne)
before August 1708 (Hans Sloane or John Chamberlayne)
8 March 1714 (Richard Waller)

Royal Society to

108 letters 13 May 1680 - 31 May 1723

Pieter vander Slaart

a few months before April 1697 from

Hans Sloane

18 December 1696 from
19 February 1697 to
25 September 1699 to
2 January 1700 to
8 June 1700 from
14 June 1700 to
9 July 1700 to
15 July 1700 from
27 July 1700 to
7 September 1700 to
26 October 1700 to
29 November 1700 from
25 December 1700 to
1701-01-28 to
24 April 1701 from
20 May 1701 from
21 June 1701 to
27 September 1701 from
18 November 1701 from
6 December 1701 to
before April 1702 from
November 1703 from
3 November 1703 to
13 February 1704 from
between March and July 1704 from
November 1704 from
13 February 1705 from
4 May 1707 from
10 September 1709 to
12 October 1713 to
24 October 1713 from

John Somers

15 November 1701 from
6 December 1701 to

Cornelis Spiering

May 1716 from
22 May 1716 to

William Stanley

21 September 1691 from

Adriaan Swalmius

August 1717 from
19 August 1717 to

Melchisedec Thevenot

October 1683 to
October 1683 from
23 September 1688 to

Ehrenfried Walther von Tschirnhaus

October 1699 to

Petrus Valckenier

11 February 1704 to

Maarten Etienne van Velden

2 May 1695 from
23 May 1695 to
30 May 1695 from
12 July 1695 to
26 October 1696 to
4 February 1697 from
12 February 1697 to

Lambert van Velthuysen

12 April 1679 from
11 May 1679 to
June 1679 from
13 June 1679 to
17 June 1679 from
11 July 1679 to
18 October 1679 from
14 November 1679 to

Fortunato Vinaccesi

27 November 1698 from

Richard Waller

12 February 1692 from
22 April 1692 to
8 May 1693 from
1 July 1693 to
8 December 1693 to
19 January 1694 to
10 February 1694 from
12 February 1694 to
2 May 1694 from
26 May 1694 to
14 September 1694 to
3 March 1714 from
19 July 1714 from
27 July 1714 from
30 August 1714 from

Angelus van Wikhuysen

before September 1695 from
15 July 1707 from
1707 to

Joseph Williamson

14 February 1678 to

Nicolaas Witsen

1696 from
8 March 1696 to
6 July 1696 to
10 July 1696 to

Christopher Wren

22 January 1683 to
16 July 1683 to

Harmen van Zoelen

November 1696 to
1698 to
17 December 1698 to
1699 to
26 April 1699 to

miscellaneous / unnamed

1683 to unknown
August or September 1683 from two noblemen
15 March 1686 from a Prussian doctor
before July 1695 from a doctor from Zeeland
before November 1695 from His Excellency Mr.
30 October 1696 to N.N. (a gentleman from Brabant)
November 1696 from a gentleman from Brabant
1 February 1699 to N.N. (Right Honourable Sir)
5 August 1699 to N.N. (directors of the United East India Company in Delft)
16 June 1700 to N.N. "Highly Learned Sir"
August 1700 to N.N. "Your Most Serene Highness"
8 April 1701 to N.N. (Mayors and governors of the City of Delft)
6 March 1717 to N.N. (Members of the Royal Society)
6 March 1717 to N.N. (Members of the Royal Society)

Sources

Year	Author	Title
1662 - 1740	various	Letter Book Original
1692 - 1702	Rabus, P. ed.	De Boekzaal van Europe
1888	Huygens, C.	Oeuvres complètes
1965 – 1986	Hall, A. R. and M. B. Hall (eds.)	Correspondence of Henry Oldenburg
1996	Rusnock, A.	Correspondence of James Jurin (1684-1750)
2001	Hunter, M., et al. ed.	Correspondence of Robert Boyle, 1636-1691
2007	Centre for Editing Lives and Letters (CELL)	The Hooke Folio Online

What happened?

Date	Event
February 1, 1674	Constantijn Huygens wrote Letter L-004 to Leeuwenhoek, enclosing an extract of a letter from Oldenburg that asked Huygens to encourage L.’s nature study
April 11, 1674	Constantijn Huygens wrote Letter L-007 to Leeuwenhoek about sending his observations to son Christiaan in Paris
May 4, 1674	Henry Oldenburg wrote Letter L-010 to Leeuwenhoek requesting that he examine saliva, chyle, and sweat
August 30, 1674	Henry Oldenburg wrote Letter L-013 to Leeuwenhoek, encouraging him to send more observations
November 5, 1674	Henry Oldenburg wrote Letter L-017 to Leeuwenhoek encouraging him and asking about the kind of salt he was observing
January 3, 1675	Henry Oldenburg wrote Letter L-020 to Leeuwenhoek about his doubts about globules
March 1, 1675	Henry Oldenburg wrote Letter L-023 to Leeuwenhoek in response to his Letter L-021 of 1675-01-22
April 22, 1675	Henry Oldenburg wrote Letter L-025 to Leeuwenhoek recommending that he get help from knowledgable people
August 22, 1675	Henry Oldenburg wrote Letter L-027 to Leeuwenhoek acknowledging reciept of his letters
January 7, 1676	Henry Oldenburg wrote Letter L-030 to Leeuwenhoek about the reaction in London to his observations
February 13, 1676	Henry Oldenburg wrote Letter L-032 to Leeuwenhoek requesting that he examine hair
May 14, 1676	Henry Oldenburg wrote Letter L-036 to Leeuwenhoek about Hooke's and Grew's reactions to recent observations
October 18, 1676	Henry Oldenburg wrote Letter L-041 to Leeuwenhoek; sent Philosophical Transactions no. 127
October 26, 1676	Henry Oldenburg wrote Letter L-042 to Leeuwenhoek acknowledging receipt of the letter of 1676-10-09
November 12, 1676	Henry Oldenburg wrote Letter L-046 to Leeuwenhoek that he would write at greater length soon
January 1, 1677	Theodore Craanen wrote Letter L-048 to Leeuwenhoek, some time in 1677, requesting that his relative Johan Ham be allowed to visit
February 9, 1677	Christiaan Huygens wrote Letter L-050 of 1677-02-09 to Leeuwenhoek that his observations of little animals in spice infusions were well received in France
February 22, 1677	Henry Oldenburg wrote Letter L-052 to Leeuwenhoek for more details about his method for observing little animals
March 4, 1677	Henry Oldenburg wrote Letter L-053 to Leeuwenhoek requesting that he examine muscle fibers and brains
April 20, 1677	Henry Oldenburg wrote Letter L-055 to Leeuwenhoek relaying the compliments of the members of the Royal Society
August 7, 1677	Henry Oldenburg wrote Letter L-057 to Leeuwenhoek, asking him to examine the skin of Moors and enclosing Philosophical Transactions no. 136
December 8, 1677	Constantijn Huygens wrote Letter L-062 to Leeuwenhoek about his observations of sperm
December 10, 1677	Robert Hooke wrote Letter L-063 to Leeuwenhoek to acknowledge the receipt of Letter L-060 of November 1677 to describing sperm in human semen
January 11, 1678	Nehemiah Grew and Robert Hooke wrote Letter L-065 to Leeuwenhoek asking him to further observe sperm
February 11, 1678	Robert Hooke wrote Letter L-068 to Leeuwenhoek about how he verified Leeuwenhoek’s observations of little animals in a pepper infusion
April 28, 1678	Robert Hooke wrote Letter L-072 to Leeuwenhoek that King Charles saw the little animals in pepper water
October 13, 1678	Nehemiah Grew wrote Letter L-075 of 1678-10-13 to Leeuwenhoek that Letter L-073 about male sperm and female ovulation in humans would be printed "as far as decency permits"
April 12, 1679	Lambert van Velthuysen wrote Letter L-079 to Leeuwenhoek about arteries and nerves
June 17, 1679	Lambert van Velthuysen wrote Letter L-089 to Leeuwenhoek about procreation
August 1, 1679	Robert Hooke wrote Letter L-091 of some time in August 1679 to Leeuwenhoek; now lost
October 18, 1679	Lambert van Velthuysen wrote Letter L-093 of 1679-10-18 to Leeuwenhoek about his delay in responding and gout
October 27, 1679	Robert Hooke wrote Letter L-094 of 1679-10-27 to Leeuwenhoek about examining fecund and sterile eggs for spots
February 2, 1680	Robert Hooke wrote Letter L-099 to inquire whether Leeuwenhoek would accept election to the Royal Society
March 8, 1680	Thomas Gale wrote Letter L-101, sending Leeuwenhoek official notice of his election as member of the Royal Society
April 22, 1680	Robert Hooke wrote Letter L-103 to Leeuwenhoek as official notice of his election as member of the Royal Society
July 4, 1681	Robert Hooke wrote Letter L-112 of 4 July 1681 to thank Leeuwenhoek for previous letters and to promise to respond more promptly in the future
July 17, 1681	David Gregory wrote Letter L-113 to Leeuwenhoek as cover letter for Letter L-112 from Hooke
December 1, 1681	Robert Hooke wrote Letter L-115 of some time in December 1681 to Leeuwenhoek about his previous letters
March 20, 1682	Robert Hooke wrote Letter L-117 to Leeuwenhoek that his observations were well received by the Royal Society
March 26, 1682	Robert Hooke wrote Letter L-118 to Leeuwenhoek that his observations of shellfish muscles were well received by the Royal Society and concurred with his own
February 26, 1683	Francis Aston wrote Letter L-123 of 26 February 1683 about problems translating his letters and opposition to his views
March 27, 1683	Francis Aston wrote Letter L-125 to Leeuwenhoek about new Royal Society officers
June 7, 1683	Anthoinie Heinsius wrote Letter L-127 to Leeuwenhoek about his observations concerning generation and blood circulation
September 1, 1683	Two Dutch noblemen wrote Letter L-131 some time in early September 1683 to Leeuwenhoek about the fear that kept them from attending a meeting of the Royal Society
September 10, 1683	Anthonie Heinsius wrote Letter L-133 to Leeuwenhoek about recent observations of generation
October 1, 1683	Melchisédech Thévenot wrote Letter L-138 of October 1683 to Leeuwenhoek, a courteous reply
October 8, 1683	Anthonie Heinsius wrote Letter L-139 of 8 October 1683 to Leeuwenhoek that his work was making a positive impression in Paris and that some of his letters would be published in the new Journal de Médecine
October 11, 1683	Francis Aston wrote Letter L-140 to Leeuwenhoek about the translation of a Dutch phrase concerning egg yolks
October 18, 1683	Anthonie Heinsius wrote Letter L-142 of in response to Letter L-141
January 1, 1684	Daniel Gaesbeeck wrote Letter L-145 of 1684-01-01 to Leeuwenhoek about why he was publishing his letters
March 7, 1684	Francis Aston wrote Letter L-146 to Leeuwenhoek about the importance of his work
June 7, 1684	Francis Aston wrote Letter L-148 to Leeuwenhoek to thank him for his letter with observations of the lens of the eye, which was read to the Royal Society and was well-received by them
July 24, 1684	Daniel van Gaesbeeck wrote Letter L-149 about why he was publishing more of Leeuwenhoek's “mutilated”, “mistranslated”, and “misunderstood” letters
September 15, 1684	Francis Aston wrote Letter L-151 to Leeuwenhoek that Letter L-150 had not been read by the Royal Society
January 20, 1685	Francis Aston wrote Letter L-153 to inform Leeuwenhoek that his recent letter about wine was favorably received at the Royal Society
February 19, 1685	Francis Aston wrote Letter L-156 to inform Leeuwenhoek that his Letter L-154 about salts was received but had not been read to the Society
June 27, 1685	Francis Aston wrote Letter L-158 of 1685-06-27 to pass along the recommendation by John Hoskyns that Leeuwenhoek examine silkworm eggs
August 3, 1685	Anthonie Heinsius wrote Letter L-160 to Leeuwenhoek about Robert Boyle's reaction to the letter about cochineal
August 9, 1685	Francis Aston wrote Letter L-161 of some time between August and October 1685 to inform Leeuwenhoek that Letter L-159 had been received but not yet read
August 31, 1685	Anthonie Heinsius wrote Letter L-163 of 1685-08-31 about Boyle's idea about the origin of cochineal
October 2, 1685	Karel von Hessen-Kassel wrote Letter L-165 to thank Leeuwenhoek for the visit to his house
December 17, 1685	Constantijn Huygens wrote Letter L-167 to Leeuwenhoek about root trees
March 12, 1686	Edmond Halley wrote Letter L-170, known only by reference in Letter L-176
March 12, 1686	Thomas Gale wrote Letter L-169 to Leeuwenhoek reviewing his recent "ingenious and curious communications"
March 15, 1686	A Prussian doctor wrote Letter L-171 of sometime after 1686-03-15 to request a visit, enclosing pieces of amber
March 16, 1686	Antonio Magliabechi wrote Letter L-172 to Leeuwenhoek, a "most courteous and agreeable letter"
May 25, 1686	Edmond Halley wrote Letter L-176 to Leeuwenhoek about a gift from the Royal Society and requesting some portraits
July 11, 1686	Jacob Gronovius wrote Letter L-179 to Leeuwenhoek about how his letters were received in Italy
December 1, 1686	Edmond Halley wrote Letter L-183 to Leeuwenhoek on behalf of the Royal Society, now lost
February 24, 1687	Edmond Halley wrote Letter L-184 to Leeuwenhoek on behalf of the Royal Society, assuring him that the portraits he sent are received, wondering why he has not sent any observations recently, and enclosing recent numbers of Philosophical Transactions
March 6, 1689	Christiaan Huygens wrote Letter L-205 to Leeuwenhoek, thanking him for the gift of a mangrove tree and inquires whether L.’s observations of the circulation of the blood could also be seen in the wings of bats, the legs of ducks, and the ears of rats
March 6, 1690	Christiaan Huygens wrote Letter L-208 to Leeuwenhoek about liquids in glass balls and Iceland crystal
May 27, 1691	Antonio Magliabechi wrote Letter L-209 of 1691-05-27 to Leeuwenhoek about book news and Leibniz's reaction to some of Leeuwenhoek's observations
September 21, 1691	William Stanley wrote Letter L-211 of 1691-09-21 to Leeuwenhoek, a courtesy letter
February 12, 1692	Richard Waller wrote Letter L-215 to Leeuwenhoek about his recent observations and the structure of grass
June 24, 1692	Antonio Magliabechi wrote Letter L-219 of 1692-06-24 to Leeuwenhoek about recent books that he thought might be of interest by Ramazzini and Guiglielmini
October 20, 1692	Christiaan Huygens wrote Letter L-223 to Leeuwenhoek about the procreation of eels and spontaneous generation and praised his work and diligence
May 8, 1693	Richard Waller wrote Letter L-224 to Leeuwenhoek about colors of feathers and univocal generation
August 18, 1693	Pieter Rabus wrote Letter L-226 to Leeuwenhoek praising his accomplishments and including a laudatory poem
September 3, 1693	George Garden wrote Letter L-227 to Leeuwenhoek about the role of egg and ovaries in reproduction
February 10, 1694	Richard Waller wrote Letter L-234 to Leeuwenhoek, asking him to examine the colors of birds' feathers and other bodies, such as silk, paint, and mercury and whether he had observed sperm inside of an egg
February 28, 1694	Benedictus Haan wrote Letter L-237 to Leeuwenhoek agreeing with him against George Garden about the female ovary
March 2, 1694	Antonio Magliabechi wrote Letter L-238 of sometime before 1694-03-02 to Leeuwenhoek about recent books that he thought might be of interest
May 2, 1694	Richard Waller wrote Letter L-243 to Leeuwenhoek about recent observations, to request a portrait, and to introduce Mr. Walfort, who delivered it
May 1, 1695	Pieter Rabus wrote Letter L-250 to Leeuwenhoek, a "pleasant" letter now lost
May 1, 1695	Frederick Adriaan van Reede wrote Letter L-249 sometime in early May 1695 that he was pleased with Leeuwenhoek’s observations about the apple-blossom weevil and black flies on apple tree blossoms
May 2, 1695	Maarten Etienne van Velden wrote Letter L-252 to Leeuwenhoek about two printed works and a box of flies
May 30, 1695	Maarten Etienne van Velden wrote Letter L-256 about his dissatisfaction with Leeuwenhoek's views on spontaneous generation in Letter L-255
June 1, 1695	Frederick Adriaan van Reede wrote Letter L-257 sometime in June 1695 that he was pleased with Leeuwenhoek’s further observations about garden pests
June 21, 1695	Pieter Rabus wrote Letter L-258 asking for Leeuwenhoek’s comments on a letter he had received about caterpillars that were growing in a woman’s ears
July 1, 1695	A doctor from Zeeland, Angelus van Wijkhuysen, wrote Letter L-259 to request Leeuwenhoek's opinion on the origin of flies from a dead caterpillar
September 1, 1695	A certain gentleman, Angelus van Wijkhuysen, wrote Letter L-269 before September 1695 to inform Leeuwenhoek about mussel gatherers and a minister who believed that mussels are formed by spontaneous generation
October 12, 1695	Antonio Magliabechi wrote Letter L-272 of 1695-10-12 to thank Leeuwenhoek for dedicating Arcana Natura Detecta to him and to report on several recent books written in Latin and Italian by Italians that he thought might be of interest
October 14, 1695	Antonio Magliabechi wrote Letter L-273 to praise Leeuwenhoek
October 23, 1695	Antonio Magliabechi wrote Letter L-275 of 1695-10-23 to Leeuwenhoek about recent books in Latin and Italian by Italians that he thought might be of interest
November 1, 1695	His Excellency Mr.... wrote Letter L-278 of sometime before November 1695 on the day he left Düsseldorf, a lost letter
November 5, 1695	Antonio Magliabechi wrote Letter L-280 to again praise Leeuwenhoek
February 17, 1696	Hans Sloane wrote Letter L-284 of 1696-01-17 on behalf of the Royal Society to encourage Leeuwenhoek
March 6, 1696	Antonio Magliabechi wrote Letter L-286 to Leeuwenhoek, reporting that he finally received the copies of Arcana Naturae Detecta, one for Grand Duke Cosima III
May 16, 1696	Pieter Rabus wrote Letter L-288 to Leeuwenhoek about dowsing rods
June 5, 1696	Antonio Magliabechi wrote Letter L-290 to Leeuwenhoek about the book dedicated to him
July 1, 1696	Nicolaas Witson wrote Letter L-291 of sometime before July 1696 to Leeuwenhoek about an enclosed mineral, map, and letter
July 8, 1696	Antonio Magliabechi wrote Letter L-293 to Leeuwenhoek about a packet of books that had arrived
July 30, 1696	Pieter Rabus wrote Letter L-298 to Leeuwenhoek, more about honey-dew and dowsing rods
August 23, 1696	Frederick Adriaan van Reede wrote Letter L-299 of 1696-08-23, a "welcome letter"
November 10, 1696	A gentleman in Brabant wrote Letter L-308 of sometime in November 1696 to Leeuwenhoek about his long-held Copernican ideas
December 18, 1696	Hans Sloane wrote Letter L-311 of 1696-12-18, as instructed by the Royal Society
December 18, 1696	Antonio Magliabechi wrote Letter L-310 to Leeuwenhoek with reports on several recent books that he thought might be of interest written in Latin by Italians
January 1, 1697	Gottfried Leibniz wrote Letter L-312 to Leeuwenhoek about magnets and the magnetic power of the earth
February 4, 1697	Maarten Etienne van Velden wrote Letter L-313 to Leeuwenhoek about receiving Sesde Vervolg der Brieven
April 1, 1697	Pieter vander Slaart wrote Letter L-317 some months before April 1697 about visiting Leeuwenhoek with a German doctor
May 1, 1697	Antonio Magliabechi wrote Letter L-319 in spring 1697 with a booklet by Dr. Scaramucci about elephant bones found in Saxony
May 17, 1697	John Harwood wrote Letter L-321 of 1697-05-17 to Leeuwenhoek about enclosed issues of Philosophical Transactions
June 1, 1697	Antonio Magliabechi wrote Letter L-322 with more news of recently published books in Italian and Latin by Italians; sent gift book to Leeuwenhoek
July 19, 1697	Luca Giamberti wrote Letter L-325 to Leeuwenhoek about a gift book from Magliabechi
August 1, 1697	Antonio Magliabechi wrote Letter L-326 in August 1697 with more news of recently published books in Italian and Latin by Italians that he thought might be of interest
August 18, 1697	Jan van Leeuwen wrote Letter L-327 of 1697-08-18 to Leeuwenhoek, sending a box of straw and wheat ears said to have been ruined by honey-dew falling from the sky
January 10, 1698	Antonio Magliabechi wrote Letter L-332 to Leeuwenhoek in early 1698 with reports on several recent books that he thought might be of interest written by Italians and a German
January 15, 1698	Johan Arnoldi wrote Letter L-333 to Leeuwenhoek about problems delivering Magliabechi's gift book
March 1, 1698	Antonio Magliabechi wrote Letter L-337 to honor Leeuwenhoek with a poem in praise of great erudition
March 21, 1698	Govert Bidloo wrote Letter L-338 to Leeuwenhoek about little animals in sheep's livers
June 1, 1698	Antonio Magliabechi wrote Letter L-344 to Leeuwenhoek with reports on several recent books that he thought might be of interest written in Latin and Italian by Italians
June 9, 1698	Robert Hooke wrote Letter L-345 of 1698-06-09 to Leeuwenhoek recent letters and sending copies of Leeuwenhoek’s missing numbers of Philosophical Transactions; he encourages Leeuwenhoek’s continuing research
November 27, 1698	Fortunato Vinacessi wrote Letter L-348 of 1698-11-27 to Leeuwenhoek, enclosing letters from Italy about protecting gunpowder from the effects of water
February 1, 1699	Johan Arnoldi wrote Letter L-351 to Leeuwenhoek about the pistolet that he was returning
September 8, 1699	Antonio Magliabechi wrote Letter L-359 to Leeuwenhoek with reports on several recent books written in Latin by Italians that he thought might be of interest
June 8, 1700	Hans Sloane wrote Letter L-369 to Leeuwenhoek about translation problems and parasitic worms
July 15, 1700	Hans Sloane wrote Letter L-374 to Leeuwenhoek about the three living larvae that he was sending
November 29, 1700	Hans Sloane wrote Letter L-379 of 1700-11-29 to Leeuwenhoek about the reception of his recent letters at the Royal Society
January 1, 1701	Antonio Magliabechi wrote Letter L-381 to Leeuwenhoek with reports on several recent books written in Latin by Italians that he thought might be of interest
April 24, 1701	John Chamberlayne wrote Letter L-386 to Leeuwenhoek to ask about the taste of water and whether razors are spoiled by extreme heat and cold
April 24, 1701	Hans Sloane wrote Letter L-387 of 1701-04-24 to Leeuwenhoek to introduce him to his new translator, John Chamberlayne
September 27, 1701	Hans Sloane wrote Letter L-394 to Leeuwenhoek personally thanking him for the bequest of 26 magnifying glasses
November 15, 1701	John Somers wrote Letter L-395 of 15 November 1701 to Leeuwenhoek about the bequest of 26 magnifying glasses and accepting Leeuwenhoek's unverified observations as "matters of fact"
November 18, 1701	Hans Sloane wrote Letter L-396 to Leeuwenhoek to express the thanks of the Royal Society for the bequest of 26 magnifying glasses and as a cover letter for Letter L-395 from John Somers
April 1, 1702	Hans Sloane wrote Letter L-402 of sometime before April 1702 to introduce James Vernon when he visited Leeuwenhoek
September 12, 1702	John Chamberlayne wrote Letter L-406 to Leeuwenhoek about a friend’s dental problems as well as his dental hygiene practices, enclosing one of the teeth that fell out of his friend’s mouth
November 1, 1703	Hans Sloane wrote Letter L-411 sometime before November 1703 as a cover letter for the book on Peruvian silver mines and some numbers of Philosophical Transactions
February 7, 1704	Siewert Centen wrote Letter L-417 of 7 February 1704 to Leeuwenhoek about cochineal's origin in a plant, not an insect
March 1, 1704	Siewert Centen wrote Letter L-420 in late February or early March 1704 continuing to argue that his further observations contradict Leeuwenhoek's claim that cochineal comes from an insect
March 15, 1704	Hans Sloane wrote Letter L-421 of sometime between March and July 1704 about sending a packet of Philosophical Transactions and encouraging further research
September 10, 1704	Pieter Hotton wrote Letter L-425 of sometime before 16 September 1704 to follow up on their discussion of how sap moves within plants by sending an Indian fig, two different kinds of aloes, and a plant called dragon’s blood
December 2, 1704	Hans Sloane wrote Letter L-429 of 1704-12-02 to Leeuwenhoek as a cover letter for Letter L-430 and enclosing a piece of ash from a haystack fire
December 2, 1704	John Chamberlayne wrote Letter L-430 of 2 December 1704 about a dinner with an archbishop and bishop, who gave him an odd ash from a haystack fire that Sloane had enclosed with Letter L-429
February 13, 1705	Hans Sloane wrote Letter L-432 of 13 February 1705 about recent letters and the Royal Society's good wishes
March 10, 1705	Antonio Magliabechi wrote Letter L-435 to Leeuwenhoek in early 1705 about reactions in Florence and Rome to his experiments with silver and diamonds
November 10, 1705	Hans Sloane wrote Letter L-440 of 10 November 1705 about recent letters
February 1, 1706	Francesco Corner wrote Letter L-443 to thank Leeuwenhoek for Letter L-441 about pearls
March 12, 1706	Govert Bidloo wrote Letter L-445 of 12 March 1706 as a cover letter for a recently published dissertation on the formation of chyle in the intestines
March 31, 1707	John Chamberlayne wrote Letter L-450 to inquire about Leeuwenhoek's health
May 4, 1707	Hans Sloane wrote Letter L-451 to Leeuwenhoek about not having received letters from him and to introduce visitor Gilbert Burnet
June 3, 1707	Hans Sloane wrote Letter L-453 on behalf of the Royal Society about recent letters and numbers of Philosophical Transactions
July 15, 1707	Angelus van Wikhuysen wrote Letter L-456 of 15 July 1707 in defense of using cinchona bark as medicine
November 4, 1707	Hans Sloane wrote Letter L-460 of 4 November 1707 on behalf of the Royal Society about recent letters and as cover for an enclosure of a "hairy substance"
July 10, 1708	Antonio Magliabechi wrote Letter L-465 to Leeuwenhoek with reports on several recent books that he thought might be of interest
August 1, 1708	Hans Sloane wrote Letter L-466 of sometime before 28 August 1708 on behalf of the Royal Society that recent letters have been received with pleasure and read to the attentive members
August 13, 1709	John Chamberlayne wrote Letter L-469 to Leeuwenhoek to ask again about razors and the effects of cold weather on their performance
December 1, 1709	Hans Sloane wrote Letter L-473 to introduce a visitor, Alexander Stuart, as a curious world traveler.
August 2, 1711	James Petiver wrote Letter L-478 of 2 August 1711 to Leeuwenhoek to complain about what happened when he tried to visit
October 1, 1713	Antoni Cink wrote Letter L-498 of sometime in October 1713 to ask Leeuwenhoek to examine sage leaves
October 24, 1713	Hans Sloane wrote Letter L-500 to Leeuwenhoek about responses to his recent letters
March 3, 1714	Richard Waller wrote Letter L-502 of 3 March 1714 to discuss recent observations about muscles
March 8, 1714	Richard Waller wrote Letter L-503 to Leeuwenhoek on behalf of the Royal Society about recent observations on muscle fibers and numbers of Philosophical Transactions
July 19, 1714	Richard Waller wrote Letter L-505 to Leeuwenhoek about how the Royal Society received his observations
July 27, 1714	Richard Waller wrote Letter L-506 about Letter L-504 and promised to publish whatever Leeuwenhoek sent
August 30, 1714	Richard Waller wrote Letter L-508 to Leeuwenhoek about the receipt of his latest letter and the Royal Society's annual recess
February 28, 1715	Anthonie Heinsius wrote Letter L-515 of 1715-02-28 to thank Leeuwenhoek for the letters sent by him over the years and expects that posterity will be grateful for what he has discovered
July 2, 1715	Antoni Cink wrote Letter L-517 of 2 July 1715 to Leeuwenhoek about his colleagues' reaction to Letter L-516 about muscle fibers
August 5, 1715	Gottfried Leibniz wrote Letter L-520 to Leeuwenhoek about sperm and encouraging young people and training students
October 29, 1715	Gottfried Leibniz wrote Letter L-522 to Leeuwenhoek about his observations and teaching his methods to students
March 31, 1716	Gottfried Leibniz wrote Letter L-528 to Leeuwenhoek about membranes, multiple births, and reproduction; he did not mention students
May 1, 1716	Cornelis Spiering wrote Letter L-529 in May 1716 to Leeuwenhoek about an accident in which a large carp from his pond died; encloses some scales
May 24, 1716	Antoni Cink, Ursmer Narez, and Hendrik Jozef Rega, professors in Louvain, wrote Letter L-534 of 1716-05-24 to tell Leeuwenhoek how important they think his work is, well deserving of the accompanying honorary medal and laudatory poem
September 25, 1716	Gottfried Leibniz wrote Letter L-539 of 28 September 1716 to report that he has forwarded Leeuwenhoek's Letter L-532 about ovaries to two doctors in Leipzig
October 10, 1716	Herman Boerhaave wrote Letter L-541 to Leeuwenhoek in response to Letter L-540 about coconuts
November 4, 1716	Herman Boerhaave wrote Letter L-542 to Leeuwenhoek that his discoveries and thoughts are agreeable to him
August 1, 1717	Adriaan Swalmius wrote Letter L-555 to Leeuwenhoek sometime in August 1717 to ask whether Leeuwenhoek had studied a chicken’s egg shell and the membrane within it
February 22, 1722	James Jurin wrote Letter L-571 to Leeuwenhoek summarizing and praising his life's work
May 26, 1722	James Jurin wrote Letter L-575 asking Leeuwenhoek to send Latin translations of his letters and passing along Hans Sloane's request for Leeuwenhoek to investigate smallpox pustules for insects
October 12, 1722	James Jurin wrote Letter L-580 to Leeuwenhoek, saying that his ideas about pocks are acceptable to the Royal Society
January 4, 1723	James Jurin wrote Letter L-582 to Leeuwenhoek about how to measure his microscopic observations
July 6, 1723	James Jurin wrote Letter L-586 to introduce Matthew Raper to Leeuwenhoek and continue the discussion about blood globules and generation