To be productive even as a nonagenarian requires a special order of persistent motivation. We have an example of a physician still active in his 90's in Parkes Weber who has published his Fourth Series of "Miscellaneous Notes." They range from "Echinococcus in Rabbits through Biliousness" to "Retrograde Peristalsis in Functional Nervous Conditions." The essay on "Retrograde Peristalsis," originally published in The Medical Press about ten years ago, is an excellent resumé of medical writings on this subject (about which there is considerable fanciful speculation and a minimum of objective fact).
So we have another item to add to the list of more than one thousand papers and books by a distinguished connoisseur of the unusual who is remembered in many an eponymic title for rare diseases.