Visited by Karl von Hessen-Kassel and Willem Meester

October 6, 1685

In October 1685, shortly before Constantijn Huygens wrote to his son Christiaan about it, Karl von Hessen-Kessel visited Leeuwenhoek at his home laboratory. Hessen-Kessel was accompanied by Willem Meester, a Dutch army engineer and explosives expert who had worked with Christiaan for many years.


Letter from Constantijn Huygens to his son Christiaan, November 5, 1685, no. 2408 in Huygens' Ouvres Completes.

He (Meester) had gone with him (Karl, Landgraaf van Hessen-Kassel) to Leeuwenhoeck’s, who had wanted to show him only those of his microscopes that he showed to everyone, which little glasses had at least a focal distance equal to the back of a household knife. When the Landgrave asked whether he could have some that he had made, he replied with great pride that he never gave any to anybody, nor intended to do so, and that if once he were ever to submit to that, he would soon be enslaved to everyone, and other things of that nature. After showing three or four of his microscopes, he carried them off, and went to fetch as many others, saying that he did this for fear that any of them might get mislaid in the hands of the spectators, that he did not trust people, especially Germans, repeating this two or three times. Oh, what a brute!