Roland adds nothing to the text of Roger. But The Four Masters (Quatuor Magistri, about A.D. 1270) suggest that the canula be made of the trachea of some animal, and add:
Canellus autem per processum temporis putrefit et emittur per egestionem, et iterum per concavitatem canelli transibit egestio.
In his further discussion of wounds of the intestine and their treatment Gilbert also volunteers the information that:
"Mummy (shade of Lord Lister!) is very valuable in the healing of wounds of the intestine, if applied with some astringent powder upon the suture."
In amends for the mummy, however, we are also introduced to the practice of mediaeval anaesthesia by means of what Gilbert calls the Confectio soporifera (f. 234d), composed as follows:
R.
Opii,
Succi Jusquiami (hyoscyami),
Succi papaveris nigri, vel ejus seminis,