As one reader correctly guessed, Dr. Milan is using Ether. I wanted to use a knock-out drug appropriate to the technology of the time, which meant chloroform was out. (Or so I thought – further research showed that it was discovered in 1831, which is plenty early for LL – Whoops!) So I went with ether, because all movies have shown me that such a chemical, placed on a cloth, will instantly knock a person out. Turns out, this is not true. Ether actually doesn’t do much to knock a person out, particularly if that person is filled with adrenaline from the panic of being attacked… Suffocation, on the other hand, is quite effective. Once a person is unconscious, ether DOES help keep them under. With nasty side effects once they finally wake up.
Conclusion? MOVIES LIED TO ME! I know, I was shocked too.
Have you ever assumed something was true because film depicted it a certain way, only to discover later that Hollywood got it wrong?