Letters written by Leeuwenhoek during Period 2

Alle de Brieven / Collected Letters has over 350 letters. However, only those in this chronology that Leeuwenhoek designated Letter 1, Letter 2, etc. did he consider to contain publishable microscopic observations.

Date
April 25, 1679 Wrote Letter 28 of 1679-04-25 (AB 43) 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 of 1679-04-27 (AB 44) to Constantijn Huygens
May 11, 1679 Wrote letter of 1679-05-11 (AB 45) to Lambert van Velthuysen
May 15, 1679 Wrote letter of 1679-05-15 (AB 46) to Christiaan Huygens
May 20, 1679 Wrote letter of 1679-05-20 (AB 47) to Constantijn Huygens
June 13, 1679 Wrote letter of 1679-06-13 (AB 48) to Nehemiah Grew
June 13, 1679 Wrote letter of 1679-06-13 (AB 49) to Lambert van Velthuysen
July 11, 1679 Wrote letter of 1679-07-11 (AB 50) to Lambert van Velthuysen
October 13, 1679 Wrote letter of 1679-10-13 (AB 51) to Robert Hooke
November 14, 1679 Wrote letter of 1679-11-14 (AB 52) to Lambert van Velthuysen about gout, salt, and drinking tea
November 20, 1679 Wrote letter of 1679-11-20 (AB 53) to Robert Hooke, copying his letter of 14 November 1679 to Velthuysen about gout, salt, and drinking tea
January 12, 1680 Wrote Letter 29 of 1680-01-12 (AB 54) to Robert Hooke about the structure of wood and sperm in fish
January 16, 1680 Wrote letter of 1680-01-16 (AB 55) to Robert Hooke, enclosing a copy of the letter of 1679-05-20 to Constantijn Huygens about the number and size of little animals
February 13, 1680 Wrote letter of 1680-02-13 (AB 56) to Robert Hooke that being elected a member of the Royal Society would be an honour
April 5, 1680 Wrote Letter 30 of 1680-04-05 (AB 57) to Robert Hooke about the testicles and sperm of a rat and organisms in the gills of oysters and in the sap of vines
May 13, 1680 Wrote letter of 1680-05-13 (AB 59) 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 31 of 1680-05-13 (AB 60) to Thomas Gale about little animals in sap and whether little animals are in the air
May 13, 1680 Wrote letter of 1680-05-13 (AB 58) to Members of the Royal Society expressing his surprise and gratitude at being elected a member
June 14, 1680 Wrote letter of 1680-06-14 (AB 61) to Robert Hooke, a short cover letter
June 14, 1680 Wrote Letter 32 of 1680-06-14 (AB 62) to Thomas Gale about beer, yeast, crab's eyes in vinegar, and little animals reproducing in hermetically-sealed tubes
August 9, 1680 Wrote letter of 1680-08-09 (AB 63) to Robert Hooke to ask whether the Royal Society received previous letters and to promise further investigations into the formation of blood
September 28, 1680 Wrote letter of 1680-09-28 (AB 64) to Thomas Gale to inquire whether his letter of 1680-06-14 to Hooke had arrived
November 12, 1680 Wrote Letter 33 of 1680-11-12 (AB 65) 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 4, 1681 Wrote Letter 34 of 1681-11-04 (AB 66) to Robert Hooke about hog bristles, shedding hair, blackheads; living little animals in excrement, horse urine, clay, and gout
March 3, 1682 Wrote Letter 35 of 1682-03-03 (AB 67) 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
April 4, 1682 Wrote Letter 36 of 1682-04-04 (AB 68) to Robert Hooke
July 28, 1682 Wrote letter of 1682-07-28 (AB 69) to Robert Hooke
January 22, 1683 Wrote Letter 37 of 1683-01-22 (AB 70) 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
May 20, 1683 Wrote letter of 1683-05-20 (AB 71) to Anthonie Heinsius
July 16, 1683 Wrote Letter 38 of 1683-07-16 (AB 72) to Christopher Wren
July 22, 1683 Wrote letter of 1683-07-22 (AB 73) to Anthonie Heinsius
September 2, 1683 Wrote letter of 1683-09-02 (AB 74) to Anthonie Heinsius
September 16, 1683 Wrote letter of 1683-09-16 (AB 75) to Anthonie Heinsius
September 17, 1683 Wrote Letter 39 of 1683-09-17 (AB 76) to Francis Aston about saliva and bacteria in tartar, nasal hairs and blackheads, skin, fish scales, pores, and calluses
September 30, 1683 Wrote letter of 1683-09-30 (AB 77) to Anthonie Heinsius
October 14, 1683 Wrote letter of 1683-10-14 (AB 78) to Anthonie Heinsius
December 28, 1683 Wrote Letter 40 of 1683-12-28 (AB 79) to Francis Aston
April 14, 1684 Wrote Letter 41 of 1684-04-14 (AB 80) to Francis Aston about lenses and corneas, the function of eye-lids, the involuntariness of blinking, the optic nerve, and the skin of Moors
July 25, 1684 Wrote Letter 42 of 1684-07-25 (AB 81) to Members of the Royal Society about parts of the brain of several animals, chalk stones of gout, leprosy, and the scales of eels
January 5, 1685 Wrote Letter 43 of 1685-01-05 (AB 82) to Members of the Royal Society
January 23, 1685 Wrote Letter 44 of 1685-01-23 (AB 83) to Members of the Royal Society
March 30, 1685 Wrote Letter 45 of 1685-03-30 (AB 84) to Members of the Royal Society
July 13, 1685 Wrote Letter 46 of 1685-07-13 (AB 85) to Members of the Royal Society about reproduction of trees, transfer of nutrients, male and female trees, hazelnut, comparison of reproduction of mammals with the reproduction of plants, cross-breeding, and germinati
August 10, 1685 Wrote letter of 1685-08-10 (AB 86) to Anthonie Heinsius
September 21, 1685 Wrote letter of 1685-09-21 (AB 87) to Anthonie Heinsius
October 12, 1685 Wrote Letter 47 of 1685-10-12 (AB 88) 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
January 22, 1686 Wrote Letter 48 of 1686-01-22 (AB 89) to Members of the Royal Society
April 2, 1686 Wrote Letter 49 of 1686-04-02 (AB 90) 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 14, 1686 Wrote letter of 1686-04-14 (AB 91) to Antonio Magliabechi
May 14, 1686 Wrote Letter 50 of 1686-05-14 (AB 92) to Members of the Royal Society about gall-nuts found on oak trees and the germination of plants
June 10, 1686 Wrote Letter 51 of 1686-06-10 (AB 93) to Members of the Royal Society about seeds of cotton, kapok, Bupariti, and coconuts, the reproduction of shrimp and lobster, and the eggs of shell fish
July 10, 1686 Wrote Letter 52 of 1686-07-10 (AB 94) 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 watertight
September 10, 1686 Wrote letter of 1686-09-10 (AB 95) to Daniël Papenbroek
October 30, 1686 Wrote letter of 1686-10-30 (AB 96) to Antonio Magliabechi