I have two books that mention sanitariums in Vincennes back in the time frame you want.The first book is a picture book from 1916 that shows a photo of Dr. Knapp's Sanitarium and a few of the Bowers-Lescher Sanitarium.The second book is from 1902 and has a drawing of Dr. Knapp's sanitarium with the following underneath: "Especially equipped for treating diseases of Eye, Ear, Nose and Throat. Twenty beds, modern operating and office rooms, Turkish and Electric Baths, Massage Treatment, Corner Fourth and Broadway."I'm guessing that Dr. Knapp is Dr. William T. Von Knappe and his biographical sketch is also in the second book although it does not mention any sanitarium in it.Dr. Knapp's Sanitarium was located at 420 Busseron and is now gone and the post office is located there now.The Bowers-Lescher Sanitarium was located at 217 N. Third St. now where the Alice Manor Apts. are.