In the late 17th century the island was called "Kaninchenwerder" ("Rabbit Island") after a rabbit breeding station set up by Elector Frederick William I of Brandenburg of the Hohenzollern dynasty. From 1685, he gave the chemist Johann Kunckel financial aid to build a glass foundry in the east of the island, the whole of which became Kunckel's property. Here Kunckel discovered a process to produce artificial ruby (red) glass. After the elector's death in 1688, however, Kunckel gained no further support from Frederick William's heir. In 1689, the foundry was destroyed by a fire (possibly caused by arson), and Kunckel left in 1692 for Stockholm to work for the King of Sweden.