The article presents sources and documentation of the material used by Alojzy Osiński when character-ising names in Bogactwa mowy polskiej. The analysis proves that the texts used by Osiński may not be indicated but the authors of them may be. The material also shows personal fascinations and interests of the lexicographer. The works used by Osiński are characterised – the author describes their influence on the structure of the entries. The article contains also the list of the authors of the sources.