Goethe and Grüner met again in the summer of 1821 when Goethe was on route to and from Marienbad and again in 1822. On September 1, 1825, Grüner visited Weimar and stayed as Goethe's guest for 10 days.
It was because of Goethe that Grüner became interested in mineralogy. They went together in search of mineralogical deposits, and Grüner began assembling his own collection of minerals. According to the auction catalogue the 39 letters are about mineralogy, paleontology, and literature, and include one to Grüner on March 15, 1832, a week before Goethe's death, when Goethe wrote "a summary of his philosophy of science." In that letter Goethe thanks Grüner for sending him a copy of a "dissertation" by "Professor Dietrich," in which "meine Farbenlehre" was favorably discussed. He then goes on:
[D]enn die Natur wird allein verständlich, wenn man die verschiedensten isolirt scheinenden Phänomene in methodischer Folge darzustellen bemüht ist; da man denn wohl begreifen lernt, daß es kein Erstes und Letztes gibt, sondern daß alles, in einem lebendigen Kreis eingeschlossen, anstatt sich zu widersprechen, sich aufklärt und die zartesten Bezüge dem forschenden Geiste darlegt. Möge mir ein solcher Antheil auch bey Ihnen und den werthen geistesverwandten Männern immerfort lebendig und wirksam verbleiben.
It seems to have been a profitable and enjoyable relationship, for Goethe also recalls an earlier outing:
Grüner published their correspondence in 1853: J.S. Grüner, Briefwechsel und mündlicher Verkehr zwischen Goethe und dem Rathe Grüner. Two of the thirty-nine letters are "autograph," meaning, I guess, that Goethe wrote them himself. Thirty-eight are signed by Goethe. Original envelopes are also included.
The letters, according to Sotheby's, "were acquired by the Austrian National Library in 1944, and have recently been restituted to the Heirs of Rudolf von Gutmann." I see that Sotheby's previously auctioned items, in 1993, from the Guttmann collection.
The Goethe letters can be yours for an estimated 80,000-100,000 British Pounds (U.S. $132,632 to $165,790).
Photo credit: Didier Descouens