Nicolai Ivanovich Andrusov

In 1889, Andrusov published a review of this expedition in Gornyi zhurnal (Mining Journal).

[2] From 1890 to 1891, he participated in a deep water expedition to the Black Sea by the Russian Geographical Society.

Andrusov was the first to propose that this substance was created by biological decomposition of life forms (bacteria) containing sulfurous compounds.

The previous year, he had learned about the death of his elder son, and suffered a stroke which resulted in paralysis of a leg and an arm.

His son Dimitrij Andrusov became a notable geologist and a member of the Slovak Academy of Sciences.