Peter, a merchant adventurer, who had migrated from Danzig to London about 1670, was also a director of the East India company.
In the same year there appeared in Danzig an anonymous satire, Pope a Metaphysician (Pope ein Metaphysiker), the authorship of which soon transpired.
Joining a Polish artillery regiment in the French service, he took part in the Russian campaign of 1812, and subsequently so brilliantly distinguished himself in the defence of Danzig (January - November 1813) that he won the cross of the Legion of Honour.
After acting as assistant in pharmacies at Quedlinburg, Hanover, Berlin and Danzig successively he came to Berlin on the death of Valentin Rose the elder in 1771 as manager of his business, and in 1780 he started an establishment on his own account in the same city, where from 1782 he was pharmaceutical assessor of the Ober-Collegium Medicum.
The name comes from Gedanum, the Latin name of Danzig.