Published Continuatio Epistolarum (Continuation of the Letters), Letters 53-60 (4th)

January 1, 1730

Langerak published it in Leiden after Leeuwenhoek's death.

It is interesting that seven years after Leeuwenhoek's death, there was enough market demand to re-print this volume. There was not enough, however, for Langerak, or any other printer, to issue the unpublished letters that Leeuwenhoek left at his death. They were already translated into Latin and all the plates for the figures had been cut.