Because he had no family or next of kin, and as was the custom at that time, without money, his remains were to be turned over for exploration, medical science and later to be interred in a pauper's grave.
Comme il n'avait ni famille, ni proche parent, ni argent, selon la coutume de l'époque, son corps devait être donné à la science pour fins d'explorations médicales avant d'être enterré dans une fosse publique.