Abraham Cornelis van Bleyswyk
By age 25, Bleyswyck was practicing medicine in Delft. He also conducted public anatomy lessons. The image on the right comes from Thomas van der Wilt's "De anatomische les door van Bleyswijk" (Anatomy lesson by van Bleyswijk).
Leeuwenhoek addressed several letters to Bleyswyck late in life, and referred to him as neef, which literally means nephew but was used at the time for any distant relative, in this case very distant. Bleyswyck's great-grandfather's brother Dirk had two sons. Evert, from his first wife, married Petronella, daughter of Adriaen Maertens Hoogenhouck (their son Dirk wrote Beschrijvinge der Stad Delft). Dirk Bleyswyck's son Francois, from his second wife, married Anna, daughter of Maarten Abrahams Hoogehouck and Sara van Berensteyn. So Abraham Bleyswyck's great-great-aunt-by-marriage Petronella Hogenhouck (and her first cousin Anna Hogenhouck) shared a grandmother and great-grandmother with Leeuwenhoek.
In 1720, Bleyswyck was the last of the two dozen Bleyswycks noted by Boitet who served on the Veertigraad after 1618. His many public offices include:
- regent of the orphanage, 1716-1747
- harbormaster, 1720-1722
- magistrate, 1723-1728
- representative to the admiralty in de Maze, 1735
- director of the Delft chamber of the V.O.C., 1738-1761
- mayor, 1740, 1741, 1744, 1745, 1751, 1756, 1757
- baljuw and dijkgraaf of Delfland, 1740
- adjunct ter dagvaart, 1742, 1746, 1758
- representative to the council, 1747
- representative to the state accounting office, 1752
In 1715, Bleyswyck married Marie Gribius (1685-1751), who was the daughter of Pieter Gribius, the clergyman who announced Leeuwenhoek's death to the Royal Society in a letter. Abraham and Maria lived in Oude Delft 157, which had earlier been owned by one of Leeuwenhoek's Hogenhouck relatives, Maerten Abrahams. Between 1740 and his death in 1761, Abraham gave more than 10,000 guldens to the orphanage in Delft.
Their son, Pieter van Bleiswijk (nl) (1724–1790), was grand pensionary of Holland from 1772 to 1787, one of the most powerful men in Europe.