Thanks, I had a feeling I was doing something wrong. Glad I asked. That makes a lot more sense.

Doing the math though, it looks like a 10/10 Master Chemyst wouldn't be able to get the Draconic Mutagen until level 20, because the effective caster level wouldn't hit 16 until Alch 10 / MC 9 and you can't take Advanced Mutagen as a perk. So, I have to ask:

Q305: Do you get anything at all for Draconic Mutagen beyond one elemental resistance and a 1/Mutation breath attack that is out-classed by Breath Weapon Bomb by that point? If it's read the same as the Beastmorph mutagens, it actually seems completely pointless.