Chronology of events:

For some events, the year is certain but the month and day are not. Example: We know only the year for the collections of Leeuwenhoek's letters published in Dutch during his lifetime.

For other events, the season or month are certain but the day is not. Example: Leeuwenhoek mentions that someone visited him "last month".

On the other hand, many events did indeed happen on the first day of a month. Example: public appointments to Delft's city offices took effect on January 1 of each year. Thus:

  • A date of January 1 in a given year may indicate that the year is certain but the month and day are not.
  • A date of 1 in a given month may indicate that the year and month are certain but the day is not.

Unless otherwise indicated, for events in England, the date given is Old Style, 10 days behind the Dutch Republic's New Style until 1700 and then 11 days behind.

Date
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
December 6, 1704 John Chamberlayne wrote to Hans Sloane that even native Dutch speakers have trouble helping him translate Leeuwenhoek's letters
December 13, 1704 Wrote Letter L-431 of 1704-12-13 to the members of the Royal Society about the origin of rock-crystal and a description and analysis of fossils of sea animals and two Roman dice all found in Switzerland and given to him by Pieter Valkenier
January 1, 1705 Peter Stout appointed assistant wine gauger
February 13, 1705 Hans Sloane wrote Letter L-432 of 13 February 1705 about recent letters and the Royal Society's good wishes
March 3, 1705 Wrote Letter L-433 of 1705-03-03 to the members of the Royal Society about silver deposits on his own hands after he mixed gold and silver with acid and treatment of a callous on his own finger with vitriol and then acid
March 3, 1705 Wrote Letter L-434 of 1705-03-03 to John Chamberlayne about vitrified matter from a haystack that had caught fire, sent to Leeuwenhoek with Letter L-429
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
March 12, 1705 Wrote Letter L-436 of 1705-03-12 to Antonio Magliabechi about precipitating silver from aqua fortis, silver sulphate crystals, their comparison with rock crystal, saltpetre, and sugar candy
March 27, 1705 Wrote Letter L-437 of 1705-03-27 to the members of the Royal Society about his theory that bark tissue is formed from wood; cross-sections and pictures of vessels and cells of bark and wood tissue of cherry, birch, cinnamon, and lime trees and from cork
March 30, 1705 Visited by Pieter Valkenier
April 24, 1705 Wrote Letter L-438 of 1705-04-24 to the members of the Royal Society about a fern and its seed capsules and an experiment to open and close them
May 25, 1705 Wrote Letter L-439 of 1705-05-25 to the members of the Royal Society about crystals from various minerals that Pieter Valkenier left after his recent visit and experiments to dissolve and recrystallize them
October 1, 1705 Visited by Francesco Cornaro
November 10, 1705 Hans Sloane wrote Letter L-440 of 10 November 1705 about recent letters
December 18, 1705 Wrote Letter L-441 of 1705-12-18 to Francesco Corner about the structure of a pearl compared to that of an oyster's shell, salts from pearls and oysters' shells heated and afterwards dissolved, and an argument against the grit of pearls as medicine
December 29, 1705 Wrote Letter L-442 of 1705-12-29 to the members of the Royal Society about pumice stone, its origins, and its salts, sponge and a theory about how it absorbs water, and coral
February 1, 1706 Francesco Corner wrote Letter L-443 to thank Leeuwenhoek for Letter L-441 about pearls
March 7, 1706 Visited by Govert Bidloo
March 7, 1706 Wrote Letter L-444 of 1706-03-07 to Govert Bidloo to follow up on his visit earlier that day about what Leeuwenhoek discovered in the intestines they had viewed
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 19, 1706 Wrote Letter L-446 of 1706-03-19 to the members of the Royal Society about an East Indian tree and mixing his own blood with the crushed seed of the tree and water, the effects of a drink made from hemp seed, and a dissected hemp seed
April 20, 1706 Wrote Letter L-447 of 1706-04-20 to the members of the Royal Society about a piece of hanged woman's intestinal wall brought to him by Govert Bidloo
June 1, 1706 Wrote Letter L-448 of 1706-06-01 to the members of the Royal Society about the structure of a sheep's spleen and a flea's organ for stinging and sucking
January 1, 1707 Wrote Letter L-449 of 1707-01-01 to Angelus van Wikhuysen about the use of cinchona bark as a remedy
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
May 17, 1707 Wrote Letter L-452 of 1707-05-17 to John Chamberlayne to complain that his four most recent letters to the Society had not been answered; about a bezoar stone and the visit of Corner; offered to send a copy of Letter L-436 to Magliabechi
May 18, 1707 The Royal Society read Letter L-452 of 1707-05-17 about bezoar stone and unanswered letters
June 3, 1707 Hans Sloane wrote Letter L-453 on behalf of the Royal Society about recent letters and numbers of Philosophical Transactions
July 1, 1707 At age 74, his 75th publication in Philosophical Transactions
July 5, 1707 Wrote Letter L-454 of 1707-07-05 to the members of the Royal Society to acknowledge the receipt of Letter L-453 and to cover the enclosed copy of Letter L-436 of 12 March 1705 to Magliabechi
July 7, 1707 Visited by Gilbert and Thomas Burnet
July 12, 1707 Wrote Letter L-455 of 1707-07-12 to the members of the Royal Society as thanks for numbers of Philosophical Transactions and as cover to a copy of Letter L-441 to Corner; mentioned the visit of Gilbert Burnet
July 15, 1707 Angelus van Wikhuysen wrote Letter L-456 of 15 July 1707 in defense of using cinchona bark as medicine
July 25, 1707 Wrote Letter L-457 of 1707-07-25 to the members of the Royal Society about cinchona bark and using it as a treatment for fever
August 10, 1707 Wrote Letter L-458 of 1707-08-10 to Anthonie Heinsius as a cover letter for a copy of Letter L-457 of 25 July 1707 to the Royal Society
October 18, 1707 Wrote Letter L-459 of 1707-10-18 to the members of the Royal Society about the fur on his own tongue after an attack of fever, the fur of a thrush patient, and a theory about the origin of tongue fur
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"
November 22, 1707 Wrote Letter L-461 of 1707-11-22 to the members of the Royal Society about a hairy substance, received with Letter L-460, supposedly excreted by a woman suffering from a kidney infection
December 6, 1707 Wrote Letter L-462 of 1707-12-06 to the members of the Royal Society about the tongue of an ox, its skin and papillae, and the tongue of a pig with its papillae and muscle fibres
January 1, 1708 Published Arcana Naturae Microscopiorum (Nature's Mcroscopical Mysteries), 19 Letters from 28 - 52 (3rd)
January 1, 1708 Wrote Letter L-463 of 1708-01-01 to the members of the Royal Society about the composition of red coral, the effects when heated and when dissolved in aqua fortis and boiling rain water, and crystals in dissolved coral
January 29, 1708 printer-bookseller Hendrik van Cronevelt buried
April 29, 1708 daughter Maria named to receive a bequest in the will of her Bisschop cousins
May 8, 1708 Bought neighboring property on Nieuwstraat
June 29, 1708 Wrote Letter L-464 of 1708-06-29 to the members of the Royal Society about his further observations of the white furry substance on his own tongue during attacks of fever
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 28, 1708 Wrote Letter L-467 of 1708-08-28 to the members of the Royal Society about how an eel's heart and the valves in the vien of its tail work; his own pulse and pulsation of the heart of an eel and a pike
October 9, 1708 Wrote Letter L-468 of 1708-10-09 to the members of the Royal Society about the mucous membrane in the palate and in the nose of a cow and about its tongue
October 15, 1708 John Chamberlayne wrote to Hans Sloane about difficulties translating Leeuwenhoek's "ungrammatical language"
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
August 22, 1709 Dr. Archibald Adams wrote a letter to Hans Sloane about the making of microscopes after he had visited Leeuwenhoek
September 10, 1709 Wrote Letter L-470 of 1709-09-10 to Hans Sloane, a cover letter for the following Letter L-471 to John Chamberlayne.
September 10, 1709 Wrote Letter L-471 of 1709-09-10 to John Chamberlayne about the cutting edge of a razor and its nicks as well as its setting and maintenance
November 22, 1709 Wrote Letter L-472 of 1709-11-22 to John Chamberlayne about human beard hairs and muscle fibres of a cod, both cut off with a razor
December 1, 1709 Hans Sloane wrote Letter L-473 to introduce a visitor, Alexander Stuart, as a curious world traveler
January 2, 1710 Visited by Alexander Stuart and two Scots gentlemen
January 4, 1710 Alexander Stuart wrote to Hans Sloane about his visit to Leeuwenhoek's house
January 14, 1710 Wrote Letter L-474 of 1710-01-14 to the members of the Royal Society about Alexander Stuart's visit, blood circulation in eels, crystallisation of sugar, minerals from Hungary, and his new fish viewer for visitors to see blood circulating in an eel's tail
January 26, 1710 cousin Elisabeth Maertens Leeuwenhoek married Leonard van Amsterdam
February 21, 1710 Wrote Letter L-475 of 1710-02-21 to the members of the Royal Society about the shape and crystallization of diamonds
June 6, 1710 Wrote Letter L-476 of 1710-06-06 to the members of the Royal Society about silver dissolved in aqua fortis
July 1, 1710 Visited again by Alexander Stuart
November 11, 1710 Wrote Letter L-477 of 1710-11-11 to the members of the Royal Society about what happened when he dissolved gold dust from Guinea in aqua regia
November 26, 1710 daughter Maria Thonis sold two little houses
November 27, 1710 Visited by John Farrington
December 4, 1710 Visited by Zacharias Conrad von Uffenbach: "more of ingenuity than foundation"
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
August 15, 1711 Wrote Letter L-479 of 1711-08-15 to Anthonie Heinsius as a cover letter for Philosophical Transactions, vol. 26, no. 319, with Leeuwenhoek's article on the pulse and copies of notes on gold from Guinea and hailstones
August 18, 1711 Wrote Letter L-480 of 1711-08-18 to James Petiver about the sperm of young rams and to explain what happened when Petiver tried to visited
September 22, 1711 Wrote Letter L-481 of 1711-09-22 to the members of the Royal Society about mites, their reproduction, eggs, larvae, a calculation of the size of a mite egg, the hair of a honey-bee, and metamorphis of larvae from dried fish into a full-grown animal
November 23, 1711 Wrote Letter L-482 of 1711-11-23 to Anthonie Heinsius about claims by Fryer and Kircher supporting spontaneous generation, which Leeuwenhoek rejected; gold, copper, and silver dissolved in aqua fortis and the separation of gold and copper
December 23, 1711 Delft's mayors annulled Leeuwenhoek's position of district supervisor
December 29, 1711 Wrote Letter L-483 of 1711-12-29 to Anthonie Heinsius, a cover letter for Letter L-484, naming the author of the article in Philosophical Transactions that he criticizes but does not name in the following letter, meant for publication
December 29, 1711 Wrote Letter L-484 of 1711-12-29 to Anthonie Heinsius to refute an article in Philosophical Transactions; he calculates the quantity of blood propelled by each heartbeat and estimates how often the total blood volume circulates through the body
February 11, 1712 Made will; he and daughter Maria universal heirs
March 1, 1712 Wrote Letter L-485 of 1712-03-01 to the members of the Royal Society about the skin and flesh of a whale, its seminal vessels, and its blood with comparisons to the blood of other fish
March 25, 1712 microscopist Nehemiah Grew died
April 12, 1712 Wrote Letter L-486 of 1712-04-12 to the members of the Royal Society about the structure of the genetalia of a female elephant and the structure of an elephant's skin
June 10, 1712 Wrote Letter L-487 of 1712-06-10 to the members of the Royal Society about little animals on a mussel's shell, the ciliar motion of the gills, and the intestines and ovaries of mussels
August 5, 1712 Appointed guardian of ? Leeuwenvelt
November 8, 1712 Wrote Letter L-488 of 1712-11-08 to Anthonie Heinsius, a cover letter for Letter L-489
November 8, 1712 Wrote Letter L-489 of 1712-11-08 to Anthonie Heinsius about the muscle fibres of a whale
November 28, 1712 nephew Adriaan Johannes Swalmius married Agatha Amelia Cocquis
December 17, 1712 Wrote Letter L-490 of 1712-12-17 to Anthonie Heinsius about salts in the blood of a shrimp and the muscle fibres and enveloping membranes of cod, shrimp, flounder, and perch
January 1, 1713 Published Cinnaber Naturalis (Natural Cinnabar), Letters 48 - 52 (2nd)
January 1, 1713 Wrote Letter L-491 of a few years before 1713 to Jan Meerman how barley is filling, but provides little nourishment, also about a membrane in the barley
February 28, 1713 Wrote Letter L-492 of 1713-02-28 to Jan Meerman about wheat and barley grains, beans, peas, and chestnuts, vessels and membranes in coconut rind, and the embryo in an apple pip and in a coconut
March 14, 1713 Wrote Letter L-493 of 1713-03-14 to Jan Meerman about the eye of a whale, the lens, and the cornea and calculations of the pressure on a whale's eye at great depth
March 25, 1713 Wrote Letter L-494 of 1713-03-25 to Adriaen van Assendelft about little hairs of a mouse, mole, cat, and rabbit all have the same shape; thick, dark bear hair, composition and color of hair, hair of deer and elk
March 29, 1713 Wrote Letter L-495 of 1713-03-29 to Anthonie Heinsius about the muscles of cows, muscle fibers of mice thinner than whales, fat particles, muscle fibers of sheep same size as of mice and oxen, though the animals differ greatly in size
June 28, 1713 Wrote Letter L-496 of 1713-06-28 to the members of the Royal Society about little animals on duckweed, muscle fiber membranes, and a list of unanswered letters; little animals in his mouth come from rinsing glasses with pond water
June 30, 1713 Wrote Letter L-497 of 1713-06-30 to Anthonie Heinsius about the composition of crabs’ eyes and lobster and crab shells, ring-shaped structures in lobster pincer shell, compared to annual rings of woody vegetation, and the lobster's muscle fiber membrane
October 1, 1713 Antoni Cink wrote Letter L-498 of sometime in October 1713 to ask Leeuwenhoek to examine sage leaves
October 12, 1713 Wrote Letter L-499 of 1713-10-12 to Hans Sloane as a cover letter for a copy of Letter L-489 on muscle fibres of a whale and a request for new numbers of Philosophical Transactions and a list of fellows of the Society to be sent to relatives in Rotterdam
October 24, 1713 Hans Sloane wrote Letter L-500 to Leeuwenhoek about responses to his recent letters
October 24, 1713 Wrote Letter L-501 of 1713-10-24 to Antony Cinck refuting, as requested, Kircher's ideas about poisonous little animals on sage leaves and spontaneous generation
November 19, 1713 nephew Jan Adriaans Swalmius baptized
December 7, 1713 nephew Adriaan Johannes Swalmius admitted as notary
January 6, 1714 cousin Maarten Pieters Hogenhouck appointed church warden, Oude Kerk and Nieuwe Kerk
January 26, 1714 daughter Maria received bequest from Bisschop estate
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
March 22, 1714 Gottfried Leibniz wrote to Louis Bourguet: "a fable of extravagant proportions"
May 9, 1714 Visited by Dr. Richard Bradley, professor of botany at Cambridge
June 22, 1714 Wrote Letter L-504 of 1714-06-22 to the members of the Royal Society to acknowledge Letter L-503 and numbers of Philosophical Transactions and to query why figures of the muscle fibres of whales were not published
July 5, 1714 Royal Society read Letter L-504 and asked Richard Waller to reply and send the numbers of Philosophical Transactions for 1713
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 17, 1714 Andries Jacobs appointed assistant city inspector / wine gauger
August 21, 1714 Wrote Letter L-507 of 1714-08-21 to the members of the Royal Society about the muscle fibres of cow, chicken, mouse, honeybee, flea, ant, and whale and the blood vessels in the leg of a fly; thanks for recent numbers of Philosophical Transactions
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
October 23, 1714 niece Maria Jans de Molijn's widowed husband Cornelis Haaxman made will
October 26, 1714 Wrote Letter L-509 of 1714-10-26 to the members of the Royal Society about muscle fibres and enclosing membranes in the legs of a mosquito, rose chafer, fly, crane fly, honeybee and cow; rectifying earlier opinion, the contractions in a muscle are spiral
November 4, 1714 Wrote Letter L-510 of 1714-11-04 to Adriaen van Assendelft, comparison between muscle fibres and a tightened rope; the shorter the rope, the quicker it can shrink; application of this comparison on the size of muscle fibres of a cow and of a mouse
November 9, 1714 Wrote Letter L-511 of 1714-11-09 to Isaac Newton, now lost, to cover Letter L-512
November 9, 1714 Wrote Letter L-512 of 1714-11-09 to the members of the Royal Society about the muscles of an ox, sheep, chicken, mouse, and hare
November 17, 1714 newphew Adriaan Johannes Swalmius married Adriana de Bries
November 20, 1714 Wrote Letter L-513 of 1714-11-20 to the members of the Royal Society about muscle fibres and tendons from a mouse leg, a duck wing, a honeybee, a polecat leg, and between the ribs of a mouse; a theory about the structure and action of tendons
January 1, 1715 astronomer Edmond Halley, editor again of Philosophical Transactions from 1715-1719, published only one letter by Leeuwenhoek
January 1, 1715 Published Continuatio Epistolarum (Continuation of the Letters), Letters 53-60 (3rd)
January 11, 1715 Wrote Letter L-514 of 1715-01-11 to Anthonie Heinsius, a cover letter for a copy of a recent letter on muscle fibres
February 27, 1715 Appointed executor of Leeuwenvelt estate
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
March 26, 1715 Wrote Letter L-516 of 1715-03-26 to Antony Cinck about the structure and action of muscle fibres and tendons from the leg of a mouse and the head of cod and a wire model of spiral contraction
July 1, 1715 Visited by Joachim Georg Reinerding
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
July 7, 1715 Wrote Letter L-518 of 1715-07-07 to Antony Cinck about contracting and stretching of muscle fibres and tendons; their connection in lobster and crab; no observed nerves between muscle fibres and membranes; cannot confirm that nerves are hollow
August 1, 1715 Wrote Letter L-519, now lost, of sometime before August 1715 to Gottfried Leibniz about his observations and recent letters
August 5, 1715 Gottfried Leibniz wrote about Leeuwenhoek to Louis Bourguet, who was "not persuaded by his hypothesis"
August 5, 1715 Gottfried Leibniz wrote Letter L-520 to Leeuwenhoek about sperm and encouraging young people and training students
August 5, 1715 Named in document using Vermeer estate as security
September 28, 1715 Wrote Letter L-521 of 1715-09-28 to Gottfried Leibniz about scholars who do not agree with Leeuwenhoek; sperm the same size in different animals; the pulse; posthumous letters; muscle fibers, tendons, and nerves; Hartsoeker; why he won't train students
October 29, 1715 Gottfried Leibniz wrote Letter L-522 to Leeuwenhoek about his observations and teaching his methods to students
November 18, 1715 Wrote Letter L-523 of 1715-11-18 to Gottfried Leibniz, a cover letter for Letter L-524
November 18, 1715 Wrote Letter L-524 of 1715-11-18 to Gottfried Leibniz about vessels in the flesh of fruit and in the seeds of various strains of pears, a pear's embryo and the structure of a pear's skin, and spiral vessels in tea-leaves
January 1, 1716 Paid the familiegeld (estate tax) of 20 gulden

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