[What remains is what should remain: using estates to construct biographies]

Estates play a major role in historical research, especially biographic research, for they supplement the official writings surrounding the individual view of a historical figure. But they nonetheless reflect only a small part of the scientific and private activities of a researcher. Moreover, before being handed over to an archive, they are also often filtered by the researchers themselves, by family members, and/or by successors to the historical figure's post. The history of an estate is thus of great importance to research. With an eye to the estates of natural scientists, the present text uses a concept of estates that includes not only the surviving texts but also artifacts with which the scientists worked. The focus will be on three physicists--Ernst Mach, Walther Gerlach, and Philipp Lenard--in order to investigate the significance of these objects for their respective biographies and for the history of physics.