Chronology of events: 1679--1686

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
January 25, 1679 Authorized to administer the estate of Ernst Gerrits de Bruijn
February 10, 1679 Appointed curator; Johannes Blaucamer guarantor
February 21, 1679 Wrote Letter L-078 of 1679-02-21 to Nehemiah Grew about cod sperm and about not finding any little animals in blood or saliva
April 1, 1679 cousin Maerten Huijchs Leeuwenhoek appointed tax master
April 12, 1679 Lambert van Velthuysen wrote Letter L-079 to Leeuwenhoek about arteries and nerves
April 25, 1679 Wrote Letter L-080 of 1679-04-25 to Nehemiah Grew about living little animals in fish, hare, and dogs and his calculation that more than ten times as many living animals come from the milt of a cod as there are people living on the Earth
April 27, 1679 Wrote Letter L-081 of 1679-04-27 to Constantijn Huygens about the number of sperm in the milt of the cod
May 1, 1679 Visited by James, Duke of York, and "several high personages"
May 4, 1679 Constantijn Huygens wrote Letter L-082 to Leeuwenhoek that his son Christiaan’s new book Dioptrica is about to be published
May 4, 1679 mentor Constantijn Huygens, writing to his son Christiaan, called Leeuwenhoek the "magician of Delft"
May 11, 1679 Wrote Letter L-083 of 1679-05-11 to Lambert van Velthuysen about people with gout
May 15, 1679 Wrote Letter L-084 of 1679-05-15 to Christiaan Huygens to explain more about his observations of little animals
May 20, 1679 Wrote Letter L-085 of 1679-05-20 to Constantijn Huygens about the number and size of the little animals he was observing
June 1, 1679 Lambert van Velthuysen wrote Letter L-086 to Leeuwenhoek about the chalky discharges from gouty skin and his well-known controversy with the conservative supporters of the House of Orange
June 13, 1679 Wrote Letter L-087 of 1679-06-13 to Nehemiah Grew asking him to acknowledge two letters from earlier that year
June 13, 1679 Wrote Letter L-088 of 1679-06-13 to Lambert van Velthuysen about the origin of life and the lack of appreciation by physicians and surgeons
June 17, 1679 Lambert van Velthuysen wrote Letter L-089 to Leeuwenhoek about procreation
July 11, 1679 Wrote Letter L-090 of 1679-07-11 to Lambert van Velthuysen about about the chalk produced by gouty patients and about bladder stones
July 20, 1679 Robert Hooke read his translation of Letter L-080 of 1679-04-25 at a weekly meeting of the Royal Society
July 27, 1679 Robert Hooke showed the Royal Society microscopical observations of the liquor in a ram's testicles
August 1, 1679 Robert Hooke wrote Letter L-091 of some time in August 1679 to Leeuwenhoek; now lost
August 10, 1679 Robert Hooke showed the Royal Society microscopical observations of a cock's testicles
August 15, 1679 Appointed city inspector of imported and exported liquids / wine gauger
August 25, 1679 Called "an unlearned, but ingenious man" by Peter Pels
September 4, 1679 colleague Nicolaas van der Sloot appointed co-wine gauger
September 17, 1679 Paid tax on his personal stock of wine
October 13, 1679 Wrote Letter L-092 of 1679-10-13 to Robert Hooke to inquire of Hooke why he had not received any correspondence from the Royal Society for months, also discussed bladder stones
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
October 30, 1679 cousin Pieter Abrahams Hogenhouck buried
November 1, 1679 Philosophical Collections number 1 published in London, including Leeuwenhoek's Letter 28 of 1679-04-25 (AB 43) to Nehemiah Grew
November 14, 1679 Wrote Letter L-095 of 1679-11-14 to Lambert van Velthuysen about gout, salt, and drinking tea
November 20, 1679 Wrote Letter L-096 of 1679-11-20 to Robert Hooke, copying his Letter L-095 of 14 November 1679 about gout, salt, and drinking tea
January 12, 1680 Wrote Letter L-097 of 1680-01-12 to Robert Hooke about the structure of wood and sperm in fish
January 16, 1680 Wrote Letter L-098 of 1680-01-16 to Robert Hooke, enclosing a copy of Letter L-085 of 1679-05-20 to Constantijn Huygens about the number and size of little animals
January 25, 1680 Robert Hooke read part of Letter L-096 of 1680-01-12 about the structure of wood
February 1, 1680 Robert Hooke read Letter L-085 to Huygens of 1679-05-20 about the number and size of little animals in ginger water
February 2, 1680 Robert Hooke wrote Letter L-099 to inquire whether Leeuwenhoek would accept election to the Royal Society
February 7, 1680 microscopist Jan Swammerdam died
February 8, 1680 Elected a member by the Royal Society
February 13, 1680 Wrote Letter L-100 of 1680-02-13 to Robert Hooke that being elected a member of the Royal Society would be an honour
February 18, 1680 cousin Margaretha (Grietjen) Huijchs Leeuwenhoek married Gijsbert Pieterse Cruijt
February 22, 1680 Thomas Gale authorized by the Royal Society to send diploma with seal to Leeuwenhoek
February 29, 1680 The Royal Society ordered that its coat of arms be engraved on the silver box holding Leeuwenhoek's diploma
March 4, 1680 The Royal Society discussed a silver box for Leeuwenhoek's diploma
March 7, 1680 The Royal Society further discussed Leeuwenhoek's diploma
March 8, 1680 Thomas Gale wrote Letter L-101, sending Leeuwenhoek official notice of his election as member of the Royal Society
March 21, 1680 Royal Society postponed reading of Letter L-085 of 1679-05-20 to Huygens
March 28, 1680 Royal Society again postponed reading of Letter L-085 of 1679-05-20 to Huygens
April 5, 1680 Wrote Letter L-102 of 1680-04-05 to Robert Hooke about the testicles and sperm of a rat and organisms in the gills of oysters and in the sap of vines
April 11, 1680 Robert Hooke read Letter L-102 of 1680-04-05 about rat sperm and organisms in gills of oysters and sap of vines
April 22, 1680 Robert Hooke wrote Letter L-103 to Leeuwenhoek as official notice of his election as member of the Royal Society
May 13, 1680 Wrote Letter L-104 of 1680-05-13 to Members of the Royal Society expressing his surprise and gratitude at being elected a member
May 13, 1680 Wrote Letter L-105 of 1680-05-13 to Robert Hooke to gratefully accept his election as a foreign member of the Royal Society and to acknowledge the receipt of his diploma
May 13, 1680 Wrote Letter L-106 of 1680-05-13 to Thomas Gale about little animals in sap and whether little animals are in the air
May 23, 1680 Robert Hooke read the three letters of 1680-05-13 thanking the Royal Society
June 14, 1680 Wrote Letter L-107 of 1680-06-14 to Robert Hooke, a short cover letter
June 14, 1680 Wrote Letter L-108 of 1680-06-14 to Thomas Gale about beer, yeast, crab's eyes in vinegar, and little animals reproducing in hermetically-sealed tubes
June 20, 1680 Robert Hooke produced the two letters of 1680-06-14 from Leeuwenhoek at a meeting of the Royal Society
June 27, 1680 The Royal Society read Letter 108 of 1680-06-14 about beer, yeast, a little animals in hermetically sealed tubes
August 9, 1680 Wrote Letter L-109 of 1680-08-09 to Robert Hooke to ask whether the Royal Society received previous letters and to promise further investigations into the formation of blood
August 13, 1680 Constantijn Huygens, jr., called Leeuwenhoek "the great man of the century"
September 28, 1680 Wrote Letter L-110 of 1680-09-28 to Thomas Gale to inquire whether Letter 107 of 1680-06-14 had arrived
November 12, 1680 Wrote Letter L-111 of 1680-11-12 to Robert Hooke about blood globules, lees of wine, globules in rain water, milk vessels, reproduction, little animals in the male seed of animals, and their incomprehensible smallness
November 21, 1680 Robert Hooke read the headings of Letter L-111 of 1680-11-12
December 5, 1680 Francis Aston promised the Royal Society to translate Letter L-111 of 1680-11-12 into English
January 1, 1681 Sat for Cornelis de Man's Anatomy Lesson of Dr. 's Gravezande
January 8, 1681 Appointed curator of the abandoned estate of Willemtie Pieters Touw
January 22, 1681 The Royal Society read Francis Aston's translation of Letter L-111 of 1680-11-12 about the lees of ale and wine
April 29, 1681 cousin Jannitgen Huijchs Leeuwenhoek buried
June 8, 1681 cousin Maria Maertens Leeuwenhoek married Jan den Appel
June 17, 1681 co-worker Daniel Bogaert buried
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
August 9, 1681 nephew Anthonij Jans de Molijn married Magdalena van Poelgeest
November 4, 1681 Wrote Letter L-114 of 1681-11-04 to Robert Hooke about hog bristles, shedding hair, blackheads; living little animals in excrement, horse urine, clay, and gout
November 12, 1681 Robert Hooke produced Letter L-114 of 1681-11-04 from Leeuwenhoek
November 19, 1681 Robert Hooke read Letter L-114 of 1681-11-04
November 26, 1681 Members of the Royal Society discussed Leeuwenhoek's observations of hair
December 1, 1681 Robert Hooke wrote Letter L-115 of some time in December 1681 to Leeuwenhoek about his previous letters
December 3, 1681 Members of the Royal Society discussed Leeuwenhoek's microscopes
December 10, 1681 Philosophical Collections number 3 published in London, including Leeuwenhoek's Letter L-111 of 1680-11-12 to Robert Hooke
January 1, 1682 Visited by Cornelis Bontekoe
January 10, 1682 Philosophical Collections number 4 published in London, including Leeuwenhoek's Letter L-114 of 1681-11-04 to Robert Hooke
January 28, 1682 Received fees from new citizens in the name of the city's camerbewaarders and messengers
February 1, 1682 Philosophical Collections number 5 published in London, including Leeuwenhoek's Letter L-116 of 1682-03-03 to Robert Hooke
March 3, 1682 Wrote Letter L-116 of 1682-03-03 to Robert Hooke about muscle fibres, hair, the cell nucleus in the erythrocytes of fishes, the liver of salmons, beards of oysters, and the structure and growth of oyster shell
March 11, 1682 Robert Hooke read the first part of Letter L-116 of 1682-03-03 about striated muscle fibres of mammals and fishes
March 18, 1682 Robert Hooke read part of Letter L-116 of 1682-03-03 about muscle fibers
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
April 1, 1682 Philosophical Collections number 7 published in London, including Leeuwenhoek's Letter L-119 of 1682-04-04
April 4, 1682 Wrote Letter L-119 of 1682-04-04 to Robert Hooke about the structure of the muscle tissue of lobsters and shrimps.
April 15, 1682 Robert Hooke read his Letter L-117 of 1682-03-20 and Leeuwenhoek's reply, Letter L-119 of 1682-04-04 about muscles of crabs, lobsters, and shrimp
April 22, 1682 Robert Hooke showed the Royal Society part of a flesh muscle in a microscope, but the rimples mentioned by Leeuwenhoek could not be seen
July 28, 1682 Wrote Letter L-120 of 1682-07-28 to Robert Hooke, now lost, asking whether figures of the anatomy of wood in Letter L-097 of 12 January 1680 will be published in print
November 19, 1682 Sold two bonds from the property of Willem Bolnes to help pay Catherina Bolnes' creditors
January 1, 1683 Visited by Marie-Anne Mancini, Duchess of Bouillon and others
January 1, 1683 Wrote Letter L-121 of some time in 1683 to an unknown "Sir"
January 22, 1683 Wrote Letter L-122 of 1683-01-22 to Christopher Wren about the function of the ovary, muscles of insects, drinking tea and mild beer, erythrocytes, and a theory on the formation of blood
February 8, 1683 Received assistant wine gauger for emergencies
February 17, 1683 The Royal Society read Letter L-122 of 1683-01-22 to Christopher Wren
February 26, 1683 Francis Aston wrote Letter L-123 of 26 February 1683 about problems translating his letters and opposition to his views
March 9, 1683 Wrote Letter L-124 of 1683-03-09 to Francis Aston promising to send observations about generation and colors
March 27, 1683 Francis Aston wrote Letter L-125 to Leeuwenhoek about new Royal Society officers
May 20, 1683 Wrote Letter L-126 of 1683-05-20 to Anthonie Heinsius about generation and about the circulation of the blood, which he intends to communicate in a letter to the Royal Society
June 7, 1683 Anthoinie Heinsius wrote Letter L-127 to Leeuwenhoek about his observations concerning generation and blood circulation
July 16, 1683 Wrote Letter L-128 of 1683-07-16 to Christopher Wren about the procreation of frogs, sperm in fowl's egg, reproduction of rabbits, little animals in frog intestines, a theory about digestion in humans and fish, and blood
July 22, 1683 Wrote Letter L-129 of 1683-07-22 to Anthonie Heinsius about Heinsius's reactions to an earlier letter
July 28, 1683 The Royal Society read Letter L-128 of 1683-07-16 about reproduction, little animals, digestion, and blood
August 4, 1683 The Royal Society discussed Letter L-128 of 1683-07-16 about the male seed in egg yolks
August 27, 1683 Francis Aston wrote Letter L-130 to Leeuwenhoek, thanking him for his recent letter and agreeing to admit two Dutch noblemen to a meeting of the Royal Society
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 2, 1683 Wrote Letter L-132 of 1683-09-02 to Anthonie Heinsius, requesting his opinion of observations in Letter L-128
September 10, 1683 Anthonie Heinsius wrote Letter L-133 to Leeuwenhoek about recent observations of generation
September 16, 1683 Wrote Letter L-134 of 1683-09-16 to Anthonie Heinsius about whether Heinsius would like a copy of his speculations on the living organisms in mouths and on the structure of the skin
September 17, 1683 Wrote Letter L-135 of 1683-09-17 to Francis Aston about saliva, nasal hairs and blackheads, skin, pores, calluses, and cleaning teeth; the discovery of bacteria in tartar
September 30, 1683 Wrote Letter L-136 of 1683-09-30 to Anthonie Heinsius, a note accompanying a copy of Letter L-135
October 1, 1683 Melchisédech Thévenot wrote Letter L-138 of October 1683 to Leeuwenhoek, a courteous reply
October 1, 1683 Wrote Letter L-137 of October 1683 to Melchisedec Thévenot with some observations
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 14, 1683 Wrote Letter L-141 of 1683-10-14 to Anthonie Heinsius in reply to his recent Letter L-139
October 18, 1683 Anthonie Heinsius wrote Letter L-142 of in response to Letter L-141
October 26, 1683 Wrote Letter L-143 of 1683-10-26 to Francis Aston in reply to Letter L-140 about egg yolks
November 3, 1683 The Royal Society read and discussed Letter L-135
November 10, 1683 The Royal Society discussed Leeuwenhoek's observations about pores in the skin in Letter L-135
December 28, 1683 Wrote Letter L-144 of 1683-12-28 to Francis Aston about human skin and its diseases, the intestines, the effects of vinegar, the intestinal wall and peristalsis, and an experiment to demonstrate the adsorption of food nutrients in the intestines.
January 1, 1684 Daniel Gaesbeeck wrote Letter L-145 of 1684-01-01 to Leeuwenhoek about why he was publishing his letters
January 1, 1684 Published Eyerstok (Ovary), Letters 37, 39 (L-122, L-135)
January 1, 1684 Published Humor Cristallinus (Crystalline Humor), Letter 41 (L-147)
January 1, 1684 Published Onsigtbare Geschapene Waarheden (Invisible Creation Truths), Letters 32, 33, 39 (L-108, L-111, L-135)
January 1, 1684 Published Schobbens in de Mond (Scales in the Mouth), Letter 40 (L-144)
January 6, 1684 Authorized as curator to inspect estate of Willemtie Pieters Touw by her heir
February 23, 1684 The Royal Society read Letter L-144 of 1683-12-28 to Francis Aston
March 7, 1684 Francis Aston wrote Letter L-146 to Leeuwenhoek about the importance of his work
April 2, 1684 cousin Margrieta Maertens Leeuwenhoek married Michiel Reijniers van Hasseld
April 14, 1684 Wrote Letter L-147 of 1684-04-14 to Francis Aston about lenses and corneas, the function of eye-lids, the involuntariness of blinking, the optic nerve, and the skin of Moors
May 24, 1684 The Royal Society read the first part of Letter L-147 about the crystalline humour of the eye
May 26, 1684 William Molyneux demonstrated blood flow in a newt to the Dublin Philosophical Society
May 31, 1684 The Royal Society discussed Leeuwenhoek's observations in Letter L-147 about the crystalline humour of the eye
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
June 14, 1684 The Royal Society read the latter part of Letter L-147 about the crystalline humour of bird and fish eyes, the vitreous humour, the cornea tunica, and the colour of a Blackamore
June 15, 1684 Visited Christiaan Huygens in Den Haag with the Durven brothers
July 24, 1684 Daniel van Gaesbeeck wrote Letter L-149 about why he is publishing more of Leeuwenhoek's “mutilated”, “mistranslated”, and “misunderstood” letters
July 25, 1684 Wrote Letter L-150 of 1684-07-25 to Members of the Royal Society about parts of the brain of several animals, chalk stones of gout, leprosy, and the scales of eels
July 27, 1684 Christiaan Huygens gossiped about Maria Duyst in a letter to his brother Constantijn Huygens
September 15, 1684 Francis Aston wrote Letter L-151 to Leeuwenhoek that Letter L-150 had not been read by the Royal Society
December 13, 1684 sister Catharina Philips Leeuwenhoek received legacy from great uncle Johan Sebastiaans van den Berch
December 13, 1684 The Royal Society read the first part of Letter L-150 about the brain of several animals, chalk stones of gout, leprosy, and scales of eels
December 20, 1684 cousin Geertruijt Huijchs Leeuwenhoek buried
January 1, 1685 cousin Maerten Huijchs Leeuwenhoek appointed tax farmer
January 1, 1685 Published Anatomia et Contemplatio (Anatomy and Contemplation), Letters 43, 42, 38 (L-128, L-150, L-152)
January 1, 1685 Published Onsigtbare Verborgentheden (Invisible Mysteries), Letters 38, 42, 43 (L-152, L-150, L-128)
January 1, 1685 Published Sout-figuren (Salt figures), Letters 44, 45 (L-154, L-157)
January 1, 1685 Published Zaden van Boomen (Seeds of Trees), Letters 46, 47 (L-160, L-166)
January 5, 1685 Wrote Letter L-152 of 1685-01-05 to Members of the Royal Society about salts in wine and vinegar and in the stomach, the eye, the need for food and water, Descartes's theory on smallest water particles, and a theory of taste - salt, sour and sweet
January 17, 1685 The Royal Society read the latter part of Letter L-150 about the brain of an ox and a sparrow, moxa, chalk from gout, leprosy, and eels, in which he discovered both scales and fins
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
January 23, 1685 Wrote Letter L-154 of 1685-01-23 to Members of the Royal Society about salts and their crystals and his theory about the causes of taste
January 31, 1685 The Royal Society read the former part of Letter L-152 about salts in vinegar and wine, vinegar eels, and salts found in vinegar mixed with crabs eyes and chalk
February 5, 1685 Visited by Thomas Molyneux on behalf of the Royal Society
February 7, 1685 The Royal Society read and discussed the latter part of Letter L-152 salt in various wines, mixtures of tartar, crabs eyes, or chalk with wine, and the difference between salts in wines and salts in chalk stones of gout
February 13, 1685 Thomas Molyneaux wrote Letter L-155 of 1685-02-13 to Francis Aston about his visit to Leeuwenhoek's house
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
February 23, 1685 At age 52, his 25th article in Philosophical Transactions
March 30, 1685 Wrote Letter L-157 of 1685-03-30 to Members of the Royal Society about sperm, the uterus of a bitch, sheep embryos, ovaries in young animals and apples, and his claims that sperm are the life-carriers and that there are male and female sperm
April 4, 1685 The Royal Society read the former part of Letter L-154 about salts in wormwood, alum, and other substances
April 20, 1685 At age 52, his 25th letter in Philosophical Transactions
May 9, 1685 The Royal Society read part of Letter L-154 about oil of tartar, potash, and camphor
May 16, 1685 The Royal Society read the latter part of Letter L-154 about salts in ashes, lime, soda, and sal armoniac
May 28, 1685 The Dublin Philosophical Society asked the Royal Society for a copy of Letter L-154 about salts of wine and vinegar
May 31, 1685 Maria Duyst van Voorhout married Frederik Adriaan van Reede van Renswoude
June 20, 1685 The Royal Society read part of Letter L-157 about the role of eggs and male sperm in a female dog
June 22, 1685 Visited by John Locke
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
June 27, 1685 The Royal Society read the latter part of Letter L-157 about sperm and eggs in sheep and rabbits
July 2, 1685 sister Catharina Leeuwenhoek appointed as tax collector for three years
July 11, 1685 cousin Adriaen Lambrechts Leeuwenhoek appointed curator
July 13, 1685 Wrote Letter L-159 of 1685-07-13 to members of the Royal Society about reproduction of trees, transfer of nutrients, male and female trees, hazelnut, comparing reproduction of mammals with reproduction of plants, cross-breeding, and germination
July 22, 1685 Royal Society published Letter L-154, titled, “An abstract of a letter from Mr. Leewenheock, to the R. S. Dated Jan. 23rd, 1685; concerning the various figures of the salts contained in several substances”
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 10, 1685 Wrote Letter L-162 of 1685-08-10 to Anthonie Heinsius about cochineal
August 27, 1685 editor Edmond Halley did not publish any letters by Leeuwenhoek in Philosophical Transactions from 1685 to 1693
August 31, 1685 Anthonie Heinsius wrote Letter L-163 of 1685-08-31 about Boyle's idea about the origin of cochineal
September 21, 1685 Wrote Letter L-164 of 1685-09-21 to Anthonie Heinsius about cochineal
October 1, 1685 Visited by Karl von Hessen-Kassel and Willem Meester sometime in October
October 2, 1685 Karel von Hessen-Kassel wrote Letter L-165 to thank Leeuwenhoek for the visit to his house
October 12, 1685 Wrote Letter L-166 of 1685-10-12 to members of the Royal Society about the beginning of plants in seeds; chyle, sweat, about skin, optic nerve, and bile of fish; salts in beer vinegar and lemon juice; and spirits mixed with blood and wine vinegar
November 5, 1685 Constantijn Huygens Jr. wrote to his brother Christiaan about Leeuwenhoek's character and the visit by Hessen-Kassel and Meester
November 14, 1685 The Royal Society read and discussed Letter L-159 about reproduction of trees, comparison of reproduction of mammals with the reproduction of plants, and cross-breeding
December 1, 1685 Visited by De Saingermain, who later called Leeuwenhoek a "Magus"
December 17, 1685 Constantijn Huygens wrote Letter L-167 to Leeuwenhoek about root trees
December 19, 1685 Francis Aston and Tancred Robinson abruptly resigned as the secretaries of the Royal Society, just a week after they had been reelected
December 25, 1685 cousin Elisabeth Maertens Leeuwenhoek married Dirck van Schie
January 1, 1686 Published Cinnaber Naturalis (Natural Cinnabar), Letters 48 - 52
January 1, 1686 Published Levende Dierkens (Living Animals), Letters 28 - 31, 34 - 36
January 1, 1686 Sat for his oil portrait by artist Johannes Verkolje (1650-1693)
January 22, 1686 Wrote Letter L-168 of 1686-01-22 to members of the Royal Society about cinnabar naturalis, gunpowder, saltpeter, and air made by gunpowder and crab's eyes
January 23, 1686 The Royal Society read part of Letter L-166 about embryo plants in cotton seeds
February 6, 1686 The Royal Society elected Edmond Halley as clerk
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 13, 1686 The Royal Society read part of Letter L-166 about chyle, sweat, pores of the skin, the crystalline humour of the eye, and the optic nerve
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"
March 20, 1686 The Royal Society read part of Letter L-166 about gall and the scales and slime of fish
March 27, 1686 The Royal Society ordered that the unread part of Letter L-166 be read at the next meeting
April 2, 1686 Wrote Letter L-173 of 1686-04-02 to members of the Royal Society about the structure of bone, the bark of trees, skin and scales, the moisture evaporating from his body, and a little peeling piece of skin
April 3, 1686 The Royal Society asked Francis Lodwick to translate Letter L-168 about cinnebar and gunpowder
April 10, 1686 The Royal Society read and discussed Letter L-168 about cinnebar and gunpowder
April 14, 1686 Wrote letter L-174 of 1686-04-14 to Antonio Magliabechi, now lost
April 24, 1686 The Royal Society ordered that Letter L-173 be translated
May 1, 1686 The Royal Society read part of Letter L-168 about the particles composing cinnabar
May 8, 1686 The Royal Society read another part of Letter L-168 about gunpowder explosions and cannon lengths
May 14, 1686 Wrote Letter L-175 of 1686-05-14 to members of the Royal Society about gall-nuts found on oak trees and the germination of plants
May 22, 1686 The Royal Society read part of Letter L-173 about the structure of cotton seed, the sweat glands of the skin, and the slime of fish
May 25, 1686 Edmond Halley wrote Letter L-176 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, De Historia Piscium by Francis Willughby
June 5, 1686 The Royal Society read part of Letter L-173 about bone and wood
June 8, 1686 Bought a burial section in the Oude Kerk
June 10, 1686 Wrote Letter L-177 of 1686-06-10 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
June 26, 1686 The Royal Society officers declared their satisfaction with the election of Edmond Halley
July 10, 1686 The Royal Society read part of Letter L-177 about how the leaves, root, and stem are wrapped up with the seeds
July 10, 1686 Wrote Letter L-178 of 1686-07-10 to members of the Royal Society about the growth and durability of wood felled in different seasons and countries, the annual growth rings, and how wooden barrels can be made watertight
July 11, 1686 Jacob Gronovius wrote Letter L-179 to Leeuwenhoek about how his letters were received in Italy
July 17, 1686 The Royal Society ordered that Letter L-178 about the texture of oakwood be translated
September 7, 1686 Examined silkworm eggs
September 10, 1686 Wrote Letter L-180 of 1686-09-10 to Daniël Papenbroek, a cover letter for Letter L-181
September 10, 1686 Wrote Letter L-181 of 1686-09-10 to Antonio Magliabechi, a cover letter for a copy of one of his books
October 30, 1686 Wrote Letter L-182 of 1686-10-30 to Antonio Magliabechi, a cover letter for copies of two of his books
November 5, 1686 Visited by Jacob Gronovius
December 1, 1686 Edmond Halley wrote Letter L-183 to Leeuwenhoek on behalf of the Royal Society, now lost