In Thomas Norton's 15th century alchemical English poem, "The Ordinal of Alchemy", mention is made of a "booke of Meeter" (page 59 of linked scan below): https://archive.org/details/theatrumchemicum00ashm/page/58 Of this Erth showeth Albert our great Brother, In his Mineralls, which Lytharge is better than other. For the white Elixir he doth it there rehearse, And the booke of Meeter showeth it in a verse. The 17th century German poet, physician and alchemist, Michael Maier, translated Norton's poem into Latin and published it in 1618 in his Tripus Aureus, and he renders the pertinent verses as follows (page 135 of the linked scan below): https://books.google.com/books?id=t...v=onepage&q="in libro carminum" maier&f=false De hac terra Albertus Magnus meminit In mineralibus quod Lythargyrium sit optimum Pro Elixire albo, ibique recenset illud, Quod quoque in libro carminum demonstratur Maier has correctly and clearly identified Albertus Magnus' De mineralibus as the first referred source in these verses of Norton, but when it comes to identifying "the booke of Meeter" he only says "libro carminum". If Maier knew what specific book was Norton referring to by such an apparently vague title, he did not bother to clarify it for his readers. Since the majority of Norton's sources were in Latin, I suspect that this vaguely referred to source was likely also a Latin text. Does anyone here have any idea about what book could Norton have had in mind by this "book of Meeter"? Was there any Latin or vernacular text, or texts, which went by or were popularly known under such a general vague title?