Appointed curator of estate of Henricus van Zuijlen

On this day, Leeuwenhoek was appointed curator of the estate of Henricus van Zuijlen. He had been born in Utrecht, son of Huybert van Zuijlen, a chuch official of St. Marie of Utrecht, and Alith van der Well. They were married in 1630 and Huybert died in 1635, so Henricus was born between those years. In 1639, his mother married widower Dirck Jans van der Lee, a member of the Veertigraad in Delft and former mayor, magistrate, and orphan master there. They married in Utrecht but lived in Delft, which is where Henricus must have grown up.

By 1675, Henricus was living in the East Indies, where he died. Because his inheritance from his father had passed to his mother, determining its disposition drove Henricus's brothers, sisters, and heirs to Delft's mayors. They appointed camerbewaarder Leeuwenhoek to curate the estate. His mandate was to "promote the greatest justice and profit of the estate, as well as of the creditors and others entitled to do so."

It is unclear what oath Leeuwenhoek took on 26 June 1675. No other documents have been found concerning this estate or Leeuwenhoek's role in curating it.