Of keys and gates (1)

The characterisation (e.g. in the BL catalogue) of the material on fol. 32-52 of Sloane MS. 3824 as "extracts from Cornelius Agrippa's Occult Philosophy" is not completely accurate and appears based on a careless reading of the scribal notes on fol. 30r & 31r combined with not checking against the passages that actually appear on the following pages.

Rather, it appears that the scribe (generally believed to be Elias Ashmole) had before him (a) the codex now known as BL Sloane MS. 3825, of which fol. 3-95 (current numbering) contain a treatise on angel-magic known as the Janua Magica Reserata (lit. "the Magical Gate Unlocked"), and (b) another codex containing the preliminary chapters of the Janua (up to the start of the "Isagogicall Observations" at fol. 40r) with ten substantial interpolations assigned to a "Dr. R."; and these interpolations are what follows.  The letters A to K in Sloane MS. 3825 are the insertion marks for these interpolated sections.

[I will post them when I've finished transcribing them, which may take a while.]

Identifying "Dr. R." with the "Dr. Rudd" from whose papers Harley MSS. 6479-6486 were said to have been copied (although the authority for this statement is a known liar and plagiarist) is made ever so slightly problematic by the fact that the "Dr. R." interpolations into the Janua that Ashmole copied do not, in fact appear, in "Dr. Rudd's" version of the Janua (Harley MS. 6482); in fact, none of preliminary theoretical part of the Janua (Sloane MS. 3825 fol. 2r-40r) was copied into Harley 6842; what parallels there are are consistent with independent derivation from the same (mostly printed) sources (e.g., there is some overlap between the two in the material drawn from Agrippa).

The cribs from "Dr. French his translation of Cornelius Agrippa his Occult Philosophy" spotted by Ashmole were in portions, though not the entirety, of the excerpts copied and the original text of the Janua.  A typeset of the Janua can be found in Skinner & Rankine's Keys to the Gateway of Magic. 

[I have to keep reminding myself, that as much as I keep facepalming at the editors' myth-making, shaky logic and presenting speculation as fact, it is unfair to critique that book for not being something it was never advertised as, and probably never intended to be: the important questions for the target audience are not "who wrote this and when?" "which bits of this text, if any, are original compositions, and which copied from printed books?" or even "what ideas influenced the author of this, and what was its subsequent influence?" so much as "can I usefully incorporate this material into my personal practice, and if so, how?"]

The Janua as a whole is much more deserving of the title A Treatise on Angel Magic than Harley 6482, which stripped out the material giving the theoretical basis for the whole thing & replaced it with a mishmash of excerpts.  EDIT: the preliminary sections of the Janua are themselves largely quoted and paraphrased from other works, but they have been edited and arranged to develop a theme and set the stage for the practical part, whereas the excerpts in Harley 6482 were probably copied into the notebook independently of, and prior to, the "Celestial Keys."

While I don't want to be too dogmatic on this point, the stylistic similarities and shared phrasing in the two works suggests that the Janua and "The Practice of the Tables" (i.e. the text on invocation of angels in Sloane MSS. 307 & 3821) were the work of the same author; indeed, the final set of conjurations in the latter work are titles Janua <direction> Reserata.

EDIT: dammit I fail Latin, Janua is fem. sing. not neut. pl.  Fixed.