I need a new drug...? about drug in late 1800s

I'm hoping someone has an answer for this.

Were there any drugs in the last quarter of the 1800's that would have the same effect as some of the 'twilight' sedation drugs today. It could be something that would have to be administered by a doctor.

1. I need this character awake and aware, but not able to physically stop someone from doing what they are about to do.

2. Would they still feel pain with this particular drug?

3. I also need the character's memory of what happened to be clouded directly after the event then slowly come back in small doses. Would that be a possible side effect using that drug?

Thanks for any & all help!

Thanks so much! That gives me something to search for.

Will look into all of those to see which would work best for the 'evil' scene that awaits.

From the research I've found so far, the chloral hydrate seems to be exactly what I'm looking for.

I may mix it with the absinthe, based on a newspaper article I just found that is sooooo similar to the scene I have in mind, it's freaky.

I will take a look at curare too.

thanks!