Louis would go on to use statistical methods to evaluate the different aspects of the disease's progression, the efficacy of various therapies and individuals'susceptibility, publishing an article in the " Annales d'hygi�ne publique " entitled " Note on the Relative Frequency of Phthisis in the Two Sexes . " Another good friend and co-worker of Laennec, Gaspard Laurent Bayle, published an article in 1810 entitled " Recherches sur la Pthisie Pulmonaire ", in which he divided pthisis into six types : tubercular phthisis, glandular phthisis, ulcerous phthisis, phthisis with melanosis, calculous phthisis, and cancerous phthisis.
