One of most enlightened members of Demidoff's family. He learned at Goettingen University and Freiburg Mining Academy, visited C. Linnaeus in Uppsala. He was doctor honoris causa of Moscow University. His Museum of Natural History he had donated to Moscow University in 1802 became his most prominent input in developments of natural history sciences in Russia. This gathering of coins, minerals, herbs and animals, together with excellent library, was known as Demidoff's Museum. Besides this collection proper, he endowed great amount of money to support both the Museum (as a part of University's Cabinet) and his curator and director (G. Fischer became the first one). To acknowledge this contribution, Demidoff's Department of Natural History was established in 1804 in Moscow University.Demidoff's Museum was originally placed in a separate building and was accessible to its owner's friends only. Its zoological portion included 15 stuffed mammals, 115 birds, 30 fishes and reptiles, many insects and mollusk shells. A complete catalogue of this Museum was prepared and published by G. Fischer in 1807. Unfortunately, most of the original Demidoff's specimens were destroyed by the fire in 1812, only small number of the shells survived. Nearly 700 of them are known now to be kept in the collections of the Zoological Museum of Moscow University, including type specimens of 41 mollusk species.