The nineteenth Enochian Call is a single text recited with the name of whichever of the thirty Aethyrs is worked, which is why the corpus is traditionally counted as forty eight keys rather than nineteen: eighteen fixed calls, received through Edward Kelley in 1584 and published in Meric Casaubon's 1659 edition of Dee's spiritual diaries, and this one call standing for the thirty, recited once for each Aethyr in turn.
That structure sets the nineteenth call apart from every other call in the corpus. The first eighteen are fixed texts, two general openers and sixteen calls for the four Elemental Watchtowers; the nineteenth is a single template with one variable, the Aethyr's name, substituted in turn across all thirty. Dee's own angelic informant, Illemese, frames the whole set of nineteen as entrances into knowledge of the mystical tables, and the nineteenth call is the entrance into the thirty Aethyrs specifically, the aethyric ranks that sit outside the four Watchtowers' elemental structure altogether.
Casaubon's 1659 printing is again the manuscript basis for the call's text, alongside Dee's own diary record of the sessions in which Kelley scried it. No version of the call exists independent of that transmission, and every later working of the thirty Aethyrs, whether Dee and Kelley's own or a modern practitioner's, recites the same nineteenth call with only the Aethyr's name changing.