Hmm.

[ He has to give that some thought, largely because there is a lot of information he could give in response to that and he's trying to narrow down what Alucard probably needs. ]

I'll spare you the history of the Renard branch of the family and the theories on what blood can and can't be turned and- We've been using the technique for maybe two centuries now. Usually to- exsanguination was always a pretty fucking common risk, and it's meant to help with that if you get there in time. Sometimes to get the sacrament into the body, to avert turning. I only saw it done a few times, but-

[ He rolls up one sleeve, so to point to places on his own arm as an example. ]

You make a cut here, usually. [ He points to the inside of his elbow. ] And you have a- it's a tube of thin metal. You put it in there. And you make a poultice of clay and- some herb or another, pack it around the tube to make a seal. Then you do the same on the other side, either with the person or animal that the blood's being taken from or with the bottle of the sacrament. You have to keep the patient lower down, and whatever they're receiving blood from higher up.