Clemens Winkler is provided with a new…

Clemens Winkler is provided with a new mineral, called argyrodite, from the Himmelsfürst mine near Freiberg in 1886.

The mineral as been found by chemists to contain silver and sulfur.

When Winkler subsequently analyzes the mineral, he finds that the individual components only add up to about 93–94% of its total mass, leading him to suspect that a new and previously unknown element must be present.

After additional chemical purification steps over several months, Winkler isolates the pure element, germanium, on February 6, 1886 and publishes his results.

The mineral argyrodite that is Winkler's start toward finding germanium, named for his native country, is now known to be a double sulfide with formula GeS₂ · 4Ag₂S.

To place germanium into the periodic table, Mendeleev suggests that it might be ekacadmium, an element he had predicted earlier.

In contrast, Lothar Meyer favors an identification of germanium with ekasilicon, a different predicted element.

Winkler isolates more of the pure material, and eventually obtains enough to measure some of its physical and chemical properties.

His results show unequivocally that Meyer's interpretation is the correct one and that nearly all of the new element's properties match Mendeleev’s predictions.

The close match between what had been predicted for ekasilicon and what is found for germanium is clear evidence for the utility and power of the periodic table and the concept of periodicity.

Winkler, born in 1838 in Freiberg, Kingdom of Saxony, is the son of a chemist who had studied under Berzelius.

Winkler's early education had been at schools in Freiberg, Dresden, and Chemnitz.

In 1857, he had entered the Freiberg University of Mining and Technology, where his knowledge of analytical chemistry surpassed what he was being taught there.

Sixteen years later, Winkler had been appointed a professor of chemical technology and analytical chemistry at the university.