In Isidore (translated Barney et al.) Etymologies XX which is the section on cookery, Isidore explains assus:
- Roasted (assus), something that is blazing hot, as though the word were arsus, burnt.
Two forms exist: assus and assatus. I think the first half of the word, asust- is a combination of these two. Apicius, whose book on cookery is famous, uses the verb asso; "assare jecus porcinum." (to roast pig’s liver)
Isidore also helps with the second half of the word:::
- Placentae are breads made from spelt. Some people call them libum; because they are agreeable (libere) and pleasing (placere).
(Spelt is a primitive wheat; it has half the number of chromosomes found in cultivated varieties) Libar, here as ilbar, is likely to be a syncopated back-formation of from Libarius, a cook who sold these small libus or libum birthday cakes.
Verecunnus libarius hic and Pudens libarius,
which can be roughly translated as 'Verecunnus and Pudens sell votive bread here'. (graffiti on the precinct wall of the Temple of Apollo)
This creates a new problem. Beaver scent has nothing whatever to do with the musk deer in the picture. And "Blistering hot cup-cakes" is much more suitable as a description of roast chestnuts straight from the fire: castaneae, here written castanee on the left of the page. A misunderstanding seems to have arisen because because castanea, the word for chestnut, is a direct borrowing from Greek. Isidore's Etymologies p.144 provides a specious answer, which connects the chestnut tree to beaver and to musk::
Latin speakers name the chestnut (castanea)from a Greek term, for the Greeks call it καστάνια, because its paired fruits are hidden in a small sack like testicles, and when they are ejected from it, it is as if they were castrated (castrare).
It fits in perfectly with the story of beavers (Castores) making themselves valueless to hunters. And explains why this Herbal got the idea that musk deer might resort to the same drastic action.
But there is no connection that I can find between the musk deer and the cryptic ".Castoreum. alio noie asustilbar"