Van Marum introduced modern chemistry in the Netherlands after the theories of Antoine Lavoisier, and several scientific applications for general use.

Then Van Marum increased this salary to 300 from 100 by adding responsibilities to his list of duties, such as a summer garden in the Rozenprieel and eliminating other expenses.

In 1808 he was asked by Louis Bonaparte to be a member of the committee for the formation of the Koninklijk Instituut along with Jeronimo de Bosch, Jean Henri van Swinden, and Martinus Stuart.

His name is associated with the Electriseermachine, the largest electricity demonstration machine with Leiden jars built in the 18th century and at the time a crowd pleaser for the young Teylers museum.

The rooms in the Grote Houtstraat were filled with stuffed animals and other "naturalia", while the summer garden was a modern continuation of Linder's old Linnaeus hortus once located behind the original city hall quarters in the Prinsenhof.

The Teyler's museum replaced him with another local artist, Wybrand Hendricks, who painted the famous oval room and many other Haarlem scenes.

[6] During the tenure of Hendriks, Van Marum himself was busy giving public demonstrations of electricity in the Oval room, but was also collecting in this period (this is why he was so involved with the lifestyle of the concierge of the Fundatiehuis, since he was there every day).

He concentrated his efforts on three aspects: 1) Greek and Latin authors, among them the church fathers, 2) Works of natural history including travelogues, and 3) natural history periodicals, including all publications of the Royal Society of London and all publications of the Dutch Society of Science, which Teyler had been a member of, but could not be on the board of, due to religious differences with the board.

The Teyler's museum created a new wing in 1996 to house a rotational display of Van Marum's library collection, such as the works of John James Audubon in combination with contemporary stuffed birds of Naturalis.