Resale price maintenance.
wA manufacturer of patent medicines had agreed with its dealers on minimum retail prices. 
wSupreme court held contract unenforceable since it violated public policy declared in Sherman: "that these agreements restrain trade is obvious."
wCourt admits that profit would go to dealers.  But why then does Dr. Miles want RPM?
wEnd­result:  RPM illegal per se.
Dr. Miles Medical v. John D. Park & Sons Co. (1911).