In 1768, Karsten published a graphic representation of infinitely many logarithms of real and complex numbers.

[1] Not satisfied with his salary, he unsuccessfully applied as a teacher at high schools in Hamburg and Stettin.

[3] But after the Duke raised his salary significantly, Karsten turned both job offers down and stayed at Bützow.

[4] In 1783, his assistant became Friedrich Albrecht Carl Gren, who would later become a prominent figure in the field of chemistry.

[5] Karsten is credited with raising chemistry to an equally accepted department beside the physics at the universities.