Master list (pdf) of all 602 L-numbers, their Leeuwenhoek number, and their Collected Letters number
He was a wool merchant. Was his wife Sophia's father Pieter van der Burch (-1607/02/10)? He was Procureur for the Vijerschare in Delft.
Sophie, Fijtgen Pieters van der Burch
Cornelia, who married Dr Cornelis Chistiaens Sinapius 1616