And there was alot of medical knowledge gained by experimentation too. One place to check that is hit or miss for confederates is the Medical and Surgical History of the Civil War if you have a library near you that has it. The surgeon general for the US government had medical records sent there and captured confederate medical records also. I have no idea what has happened to the original records but the information in series of condensed volumes in enormous and for some there are detailed records. I have to skim over stuff having a weak stomach but I was checking on one person for someone and they used either bromine or iodine (can't remember which) to treat dysentery. They ran out so they just decided to use the other which they had in stock. The soldier died. I guess it is like "well that didn't work try something else". Better to try something than nothing for sure. I'd offer to look and see if your soldier might be in there but I don't know when I can get to that library again right now. You might find a set nearer to you before then. It is just a good thing both for the men and doctors then and for researchers now that the surgeon general then had such foresight to gather as much medical knowledge as he did in one place.