Chiropractic as a noun

Last time I checked the word chiropractic was an adjective describing, ahem, doctor.
Am I crazy or has every chiropractor decided to just make themself look like a total non-schooled, back crackin’, Spine twistin’, " We don’t need no stinkin’ grammar classes! We’re freakin’ Chiropractic!" bone monkey?
school of chirpractic what?
Doctor of Chiropractic what?

The last time you checked? Just where was it that you did this?


One more time.

At least since 1903.

From the OED.

Who you gonna believe? Me or that bastard O.E.D.?