Daniel Gaesbeeck wrote to Leeuwenhoek about why he was publishing his letters

January 1, 1684

Daniel Gaesbeeck was a well-established printer in Leiden. In 1684, he took it upon himself to print six of Leeuwenhoek's letters in Dutch. Until then, Leeuwenhoek's only publications were the letters translated, excerpted, and published in Philosophical Transactions.

Without Leeuwenhoek's permission, Gaesbeeck first published two letters that had been written in 1680 but never published in Philosophical Transactions. Gaesbeeck added a dedication in the form of an open letter to Leeuwenhoek. He noted the help of Cornelis s'Gravesande and "mijn Druk-pers, mistgaders de konstige hand des Plaat-snijders, Abraham de Blois tot Delft" (my printing press, along with the skillful hand of the plate engraver, Abraham de Blois).