[3] He is thought to have composed the canons Bei der Hitz im Sommer eß ich (English: In the heat of summer I eat) and Leck mir den Arsch fein recht schön sauber (English: Lick my arse right well and clean), which were previously attributed to Wolfgang Amadeus Mozart.
[4] In 1769, during his medical studies, the famous physician Gerard van Swieten named him to serve as his assistant in the military hospital (Militärkrankenhaus).
[8] 19th-century sources describe Trnka's medical career as a distinguished one; for instance Baas (1876) lists him among the eminent physicians of the "older Vienna School".
According to Link, Trnka was a friend of the famous musical patron and organizer Gottfried van Swieten, son of Gerhard.
Trnka's "Tu sei gelosa, è vero" became Mozart's "Leck mir den Arsch fein recht schön sauber" ("Lick me in the ass right well and clean"), and Trnka's "So che vanti un cor ingrato" became Mozart's "Bei der Hitz im Sommer eß ich" ("In the heat of summer I eat"[11]).