The girl cannot stir hand or foot to save herself.

Vauquier tears the eardrops in a hurry from her ears--and there I have my drop of blood just where I should expect it to be.

But now follow this! Vauquier hides the earrings in her pocket.
She goes to bed in order to be chloroformed.

She knows that it is very possible that her room will be searched before she regains consciousness, or before she is well enough to move.

There is only one place to hide them in, only one place where they will be safe.