He also published the first monograph on the petrels, and a list of all the birds illustrated in Daubenton's Planches Enluminées and with his friend Johan Coenraad van Hasselt (1797–1823) Beiträge zur Zoologie und vergleichenden Anatomie ("Contributions to Zoology and Comparative Anatomy") that were published at Frankfurt-am-Main, 1820.
He then travelled to Java, then part of the colonial Netherlands East Indies, with his friend van Hasselt, to study the animals of the island, sending back to the museum at Leiden 200 skeletons, 200 mammal skins of 65 species, 2000 bird skins, 1400 fish,[1] 300 reptiles and amphibians, and many insects and crustaceans.
Johan van Hasselt continued his work collecting specimens, but died two years later.
The partners are buried in a single grave in the Botanical Garden, Bogor, marked with a small column.
[5] Several species have been named to commemorate his work[7] as naturalist and zoologist: Fishes Herpetofauna Birds Mammals Plants