What German doctor was also friends with Schack Carl Rantzau?
Schack Carl Rantzau Schack Carl, "rigsgreve" (von) Rantzau or Carl Schack Rantzau-Ascheberg (11 March 1717, Ascheberg estate, Holstein – 21 January 1789, Menerbes, France) was a Holstein-born Danish officer and statesman. He is notable for his friendship with Johann Friedrich Struensee and his role in the coup which led to Struensee's fall from power.
Karl Eichwald Karl Eduard von Eichwald (4 July 1795, in Mitau, Courland Governorate – 10 November 1876, in Saint Petersburg; Russian: Эдуард Иванович Эйхвальд , "Eduard Ivanovich Eykhval'd") was a Baltic German geologist, physician, and naturalist, who worked in Russia.