These 21 unpublished letters written by, to or about Gaspar Fraxinus were collected by Istvan Botta, Tivadar Vida and Tamás Grynaeus. Most of the letters were actually health reports written by Fraxinus to Count Nadasdy, though the doctor mentions various other subjects as well. We have followed the Hungarian practice in the publication. The numbers that precede the letters refer to their original date and put them in concordance with all the known Fraxinus letters. Where you find question marks with the numbers the exact date of the letter is uncertain. After the numbers there are also short summaries, and then comes the letter itself in its original language and spelling. Letters either in Latin or German have been translated into Hungarian by Tivadar Vida, and those written in old Hungarian were provided with a transcription that gives the modern spelling. Each unit is closed with the archival data: i.e. the name of the institution that has been trusted with the preservation, and the shelfmarks are indicated.