I was long puzzled to ascertain anything regarding John de Burdeus, the author of the Tract de Pestilentia, which is copied on a ?y leaf of the ms. And as no account of him exists in any Book of Reference, so far as I know, I collected in Note B what I had found. This had been printed when I read Mr. Edward B. Nicholson's interesting letter in the Academy of 12th April, 1884, identifying him with Sir John Mandeville. I have added a few paragraphs to my Note, embodying the new information, and connecting it with my own but now that Mr. Nicholson has given the clue, it is to be hoped that either he or some other labourer will follow it up and unravel more fully the history of this mysterious personage.