Chronology of events: 1673--1692

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
April 1, 1673 cousin Magdaleentje (Helena) Maertens Leeuwenhoek (1653-1720) married Johannes de Coep
April 28, 1673 Wrote Letter 1 of 1673-04-28 (AB 1) to Henry Oldenburg
May 7, 1673 The Royal Society received Leeuwenhoek's first letter
May 19, 1673 At age 40, first letter published in Philosophical Transactions
May 25, 1673 Henry Oldenburg wrote to Reinier de Graaf about the Royal Society's reception of Leeuwenhoek's first letter
August 8, 1673 mentor Constantijn Huygens wrote to Robert Hooke about Leeuwenhoek as "exceedingly curious and industrious"
August 15, 1673 Wrote Letter 2 of 1673-08-15 (AB 2) to Henry Oldenburg
August 21, 1673 mentor Reinier de Graaf buried
October 6, 1673 First letter's ten figures published in Philosophical Transactions
October 24, 1673 Leeuwenhoek's family members in 1673
November 8, 1673 Wrote letter of 1673-11-08 (AB 3) to Henry Oldenburg
November 28, 1673 Named as administrator of the estate of Willem Jans Croonenburgh
January 1, 1674 Paid the Familiegeld (estate tax)
February 12, 1674 Constantijn Huygens wrote to Oldenburg about Leeuwenhoek and his own single-lens microscope
March 10, 1674 nieces Margrieta and Maria Jans de Molijn married Arnoldus van den Heuvel and Cornelis Haaxman
March 18, 1674 sister-in-law Maria de Meij married Pieter Schepens
April 5, 1674 Wrote letter of 1674-04-05 (AB 4) to Constantijn Huygens
April 7, 1674 Wrote Letter 3 of 1674-04-07 (AB 5) to Henry Oldenburg
April 16, 1674 Wrote letter of 1674-04-16 (AB 6) to Henry Oldenburg
April 24, 1674 Wrote letter of 1674-04-24 (AB 7) to Constantijn Huygens
April 24, 1674 Appointed curator of the abandoned estate of Bartholomeus Ritmeier
May 4, 1674 Henry Oldenburg wrote to Leeuwenhoek requesting that he examine saliva, chyle, sweat, and sperm
June 1, 1674 Wrote Letter 4 of 1674-06-01 (AB 8) to Henry Oldenburg
July 6, 1674 Wrote Letter 5 of 1674-07-06 (AB 9) to Henry Oldenburg
August 1, 1674 First observed microbes
August 11, 1674 Visited by Holger Jacobæus, the Bartholin brothers, and Arent Seyn; described as "ingenious but illiterate"
August 15, 1674 Visited by Johannes Swammerdam
August 16, 1674 Ordered as curator to hand over the debt books of Bartholomeus Ritmeier
August 24, 1674 daughter Maria made a will
August 30, 1674 Henry Oldenburg wrote to Leeuwenhoek encouraging him to send more observations
September 7, 1674 Wrote letter of 1674-09-07 (AB 10) to Henry Oldenburg
September 7, 1674 Wrote Letter 6 of 1674-09-07 (AB 11) to Henry Oldenburg
October 19, 1674 Wrote Letter 7 of 1674-10-19 (AB 12) to Henry Oldenburg
October 25, 1674 The Royal Society began requiring an oath of secrecy from the members who attended meetings
November 5, 1674 Henry Oldenburg wrote to Leeuwenhoek encouraging him and asking about the kind of salt he was observing
November 12, 1674 The Royal Society read and discussed Leeuwenhoek's letter of June 1, 1674
December 4, 1674 Wrote Letter 8 of 1674-12-04 (AB 13) to Henry Oldenburg
December 21, 1674 Appointed to administer the affairs of sister-in-law Maria de Meij
December 22, 1674 sister-in-law Maria de Meij and Pieter Schepens granted a divorce
December 24, 1674 Henry Oldenburg wrote to Leeuwenhoek about his doubts about globules
December 26, 1674 Wrote letter of 1674-12-26 (AB 14) to Constantijn Huygens
December 31, 1674 sister-in-law Catharina Swalmius buried
January 1, 1675 cousin Maerten Huijchs Leeuwenhoek appointed tax farmer
January 20, 1675 Christiaan Huygens wrote to Henry Oldenburg doubting Leeuwenhoek's observations of globules
January 22, 1675 Wrote Letter 9 of 1675-01-22 (AB 15) to Henry Oldenburg
February 2, 1675 Henry Oldenburg wrote to Christiaan Huygens about doubting Leeuwenhoek's globules
February 11, 1675 Wrote Letter 10 of 1675-02-11 (AB 16) to Henry Oldenburg
February 19, 1675 Henry Oldenburg wrote to Leeuwenhoek in response to his letter of 1675-01-22
March 26, 1675 Wrote Letter 11 of 1675-03-26 (AB 17) to Henry Oldenburg
April 12, 1675 Henry Oldenburg wrote to Leeuwenhoek recommending that he get help from knowledgable people
August 14, 1675 Wrote Letter 12 of 1675-08-14 (AB 18) to Henry Oldenburg
August 22, 1675 Henry Oldenburg wrote to Leeuwenhoek acknowledging reciept of his letters
September 15, 1675 First observed microbes in rain water
December 15, 1675 Jan Vermeer, the painter, buried
December 20, 1675 Wrote Letter 13 of 1675-12-20 (AB 19) to Henry Oldenburg
January 7, 1676 Henry Oldenburg wrote to Leeuwenhoek about the reaction in London to his observations
January 22, 1676 Wrote letter of 1676-01-22 (AB 20) to Henry Oldenburg
January 26, 1676 sister-in-law Maria de Meij buried
February 13, 1676 Henry Oldenburg wrote to Leeuwenhoek requesting that he examine hair
February 22, 1676 Wrote Letter 14 of 1676-02-22 (AB 21) to Henry Oldenburg
April 5, 1676 co-worker Daniel Bogaert married Maria van Rees
April 21, 1676 Wrote Letter 15 of 1676-04-21 (AB 22) to Henry Oldenburg
April 24, 1676 Began series of experiments to observe microbes
April 26, 1676 Began Pepper 2 experiment
May 1, 1676 Constantijn Huygens wrote to Oldenburg that Leeuwenhoek gave him an issue of Philosophical Transactions
May 4, 1676 Henry Oldenburg wrote to Leeuwenhoek about Hooke's and Grew's reactions to recent observations
May 29, 1676 Wrote Letter 16 of 1676-05-29 (AB 23) to Henry Oldenburg
July 1, 1676 Visited by Christiaan Huygens during the summer; he saw the microbes in Leeuwenhoek's infusions
July 28, 1676 Wrote letter of 1676-07-28 (AB 24) to Henry Oldenburg
July 28, 1676 Wrote Letter 17 of 1676-07-28 (AB 25) to Robert Boyle
September 30, 1676 Appointed curator of estate of Catherine Bolnes, Vermeer's widow
October 8, 1676 Henry Oldenburg wrote to Leeuwenhoek; sent Philosophical Transactions no. 127
October 9, 1676 Wrote Letter 18 of 1676-10-09 (AB 26) to Henry Oldenburg
October 16, 1676 Henry Oldenburg wrote to Leeuwenhoek acknowledging receipt of the letter of 1676-10-09
October 23, 1676 mentor Cornelis 's Gravesande lent money to Sijmons Decker
October 30, 1676 Wrote letter of 1676-10-30 (AB 27) to Henry Oldenburg
November 2, 1676 Henry Oldenburg wrote to Leeuwenhoek that he would write at greater length soon
November 7, 1676 Wrote letter of 1676-11-07 (AB 28) to Constantijn Huygens
November 18, 1676 Visited by Gottfried Leibniz
November 25, 1676 Magistrates approved payment by Maria Thins so Leeuwenhoek could pay Vermeer's creditors
November 27, 1676 Wrote letter of 1676-11-27 (AB 29) to Henry Oldenburg
January 22, 1677 mentor Jacob Spoors buried
January 26, 1677 Constantijn Huygens wrote to Oldenburg about Leeuwenhoek, a "painstaking man" who should be "cherished"
January 30, 1677 cousin Lambrecht Huijchs Leeuwenhoek (1624-1701) bought A0129 Buitenwatersloot 214
February 2, 1677 Recovered twenty-six paintings from Jannetje Stevens to help pay Catherine Bolnes' creditors
February 11, 1677 The Royal Society read the first part of Leeuwenhoek's long letter of the previous October 9
February 15, 1677 Wrote letter of 1677-02-15 (AB 30) to Christiaan Huygens
February 18, 1677 The Royal Society read the second part of Leeuwenhoek's long letter of October 9, 1676
February 22, 1677 Henry Oldenburg wrote to Leeuwenhoek for more details about his method for observing little animals
March 4, 1677 Henry Oldenburg wrote to Leeuwenhoek requesting that he examine muscle fibers and brains
March 8, 1677 The Royal Society read the third part of Leeuwenhoek's long letter of October 9, 1676.
March 8, 1677 Named quartermaster of the 2nd quarter
March 12, 1677 Maria Thins filed a legal action to prevent Leeuwenhoek from selling The Art of Painting
March 15, 1677 Organized the auction of Vermeer's remaining paintings
March 23, 1677 Wrote Letter 19 of 1677-03-23 (AB 31) to Henry Oldenburg
March 25, 1677 The Royal Society published Michael Butterfield's letter about melting glass to make spherical lenses
March 25, 1677 The Royal Society published Leeuwenhoek's letter of October 9, 1676, reporting microbes in infusions
April 8, 1677 The Royal Society read Leeuwenhoek's letter of March 23, 1677
April 10, 1677 Henry Oldenburg wrote to Leeuwenhoek relaying the compliments of the members of the Royal Society
May 14, 1677 Wrote Letter 20 of 1677-05-14 (AB 32) to Henry Oldenburg
May 18, 1677 Benedict Haan and Henry Cordes wrote to the Royal Society attesting to microbes in Leeuwenhoek's infusions
May 27, 1677 The Royal Society read Leeuwenhoek's letter of May 14, 1677
June 2, 1677 Robbert Gordon wrote to the Royal Society attesting to microbes in Leeuwenhoek's infusions
July 28, 1677 Henry Oldenburg wrote to Leeuwenhoek; sent Philosophical Transactions no. 136
August 13, 1677 Aldert Hodenpijl wrote to the Royal Society attesting to microbes in Leeuwenhoek's infusions
August 21, 1677 Johannes Boogert, Robert Poitevin, and W. van der Burch wrote to the Royal Society attesting to microbes in Leeuwenhoek's infusions
August 30, 1677 Alex Petrie wrote to the Royal Society attesting to microbes in Leeuwenhoek's infusions
September 5, 1677 mentor Henry Oldenburg died in London
September 11, 1677 Visited by Hennig Brand, Hamburg merchant
October 5, 1677 Wrote Letter 21 of 1677-10-05 (AB 33) to Henry Oldenburg
October 15, 1677 The Royal Society requested that Robert Hooke try to replicate Leeuwenhoek's observations
October 16, 1677 Wrote letter of 1677-10-16 (AB 34) to William Brouncker
November 9, 1677 Wrote Letter 22 of 1677-11-09 (AB 35) to William Brouncker
November 11, 1677 Robert Hooke failed to demonstrate "minute animals" in pump water. The Royal Society read the testimonials from people in Delft.
November 15, 1677 Bought land near Berkelse Meer
November 18, 1677 Robert Hooke again failed, using an improved microscope
November 25, 1677 Robert Hooke finally succeeded in replicating Leeuwenhoek's observations of little animals
December 2, 1677 Wrote letter of 1677-12-02 (AB 36) to William Brouncker
December 8, 1677 Constantijn Huygens wrote to Leeuwenhoek about his observations of sperm
December 16, 1677 Robert Hooke demonstrated the superiority of single-lens over double-lens microscopes
January 1, 1678 Nehemiah Grew and Robert Hooke wrote to Leeuwenhoek asking him to further observe sperm
January 1, 1678 Robert Hooke's Lectures and Collections: Cometa, Microscopium published
January 14, 1678 Wrote Letter 23 of 1678-01-14 (AB 37) to Robert Hooke about human blood, blood transfusions, flea larvae, and little animals in pepper water
January 27, 1678 Robert Hooke read Letter 23 of 1678-01-14
February 1, 1678 Empowered a Gouda notary to sell Vermeer's property to help pay Catherine Bolnes's creditors
February 1, 1678 Robert Hooke wrote to Leeuwenhoek verifying his observations in pepper water
February 3, 1678 Robert Hooke produced two experiments on blood and milk and read the latter part of the letter of 1678-01-14 about phlegm and little animals in pepper water
February 11, 1678 Robert Hooke wrote to Leeuwenhoek about how he verified Leeuwenhoek’s observations of little animals in a pepper infusion
February 28, 1678 Christiaan Huygens began series of observations of microbes replicating and expanding on Leeuwenhoek's
March 17, 1678 Robert Hooke showed the Royal Society microscopical observations of tendons and little animals in anise and coffee
March 18, 1678 Wrote Letter 24 of 1678-03-18 (AB 38) to Nehemiah Grew
March 24, 1678 Robert Hooke read his paper about his microscopic observations and methods
April 7, 1678 Robert Hooke showed the Royal Society microscopical observations of muscle from a lobster's claw
April 28, 1678 Jan Swammerdam called Leeuwenhoek "biased, and reasons in a very barbarical way"
April 28, 1678 Robert Hooke wrote to Leeuwenhoek that King Charles saw the little animals in pepper water
May 5, 1678 Robert Hooke showed the Royal Society microscopical observations of the motion and composition of muscles
May 9, 1678 niece Maria Jans de Molijn buried
May 31, 1678 Wrote Letter 25 of 1678-05-31 (AB 39) to Nehemiah Grew
June 6, 1678 Christiaan Huygens wrote to Nehemiah Grew about seeing the sperm in human semen
July 4, 1678 Lambert Twent named first postmaster of Delft

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