A Prussian doctor wrote Letter L-171 of sometime after 1686-03-15 to request a visit, enclosing pieces of amber
These letters are known only by reference in another letter.
In this letter, a Prussian doctor asks to visit L. He sends two pieces of amber from Prussia. During his visit, he mentions a piece of “burned paper” that fell from the sky in Courland, a piece of which he later sends to L. in another letter.
Leeuwenhoek often omitted the names of his visitors and correspondents, even when they were otherwise well known. From what Leeuwenhoek wrote in Letter L-193 of 17 October 1687, the doctor could have sent two letters and there is no further evidence that he ever visited.
At the time, Courland was an independent duchy in what is now western Latvia.
Letter 104 [59] L-193 of 17 October 1687 to the Royal Society
A certain doctor of medicine, born in Prussia, sends me a very courteous missive, asking to be allowed to visit me; and in addition he sends me some small pieces of amber which, he says, are sent me by two prominent gentlemen in Prussia. ...
The same gentleman told me, amongst other things, that there had fallen from the sky, on a field in Courland, on the 14th or 15th of March 1686, a piece of burned paper which was quite three sheets large, of which, so he said, he had a piece that he had observed through the microscope; but that he was unable to form an opinion of it. And as I made it clear that I would like to see this alleged paper, the said gentleman sent me a piece (by letter), of which I hereby enclose about half.
