The nineteenth call's practical afterlife is dominated by a single later working: Aleister Crowley's 1911 Vision and the Voice, in which Crowley recited the call thirty times, once for each Aethyr in descending order, and recorded the visionary material each recitation produced. That record, published as Liber CCCCXVIII, is the reason the nineteenth call and the thirty Aethyr system are, for most twentieth and twenty first century readers, the most familiar part of Dee's entire angelic corpus, better known than the two general openers or the sixteen elemental calls that precede it in the Claves Angelicae.
Crowley's working was itself downstream of the Golden Dawn's earlier study of the Enochian material, documented in Israel Regardie's published editions of the order's papers, which had already brought the Calls back into ceremonial use more than two centuries after Casaubon's printing. The thirty Aethyrs themselves, and the ninety one Governors distributed across them, are catalogued separately in this atlas; the nineteenth call is the fixed text that later magicians used to approach each one, not a description of the Aethyrs' own content.
As with the rest of the Claves Angelicae, the call's only textual basis is Casaubon's 1659 edition of Dee's diaries. Vision and the Voice records what Crowley's own working produced, not an independent manuscript witness to the call's wording, and it is read here as documented modern reception rather than as evidence about Dee and Kelley's sixteenth century sessions.