Sorry to burst your bubble, learntojive but you should have cut the cutting off just below the node, thats the area where it's possible for it to produce roots.
Althogh it's possible to root magnolia cuttings like this, they can be difficult.
The best way to propagate it is to layer it by pegging a low branch (early summer) into the ground or into a pot that has been plunged into the ground. It sounds brutal but wound the branch at the point where you peg it down with a 'U' shaped piece of wire, by breaking it 1/2 way through, hopefully it will take root and you can then detatch it from the branch after about a year. Good Luck Tbird+