Why couldn't Stephan Blackpool divorce his wife?

Stephen was married nineteen years before our story began. He was very good to his wife, but she became a drunkard and sold the furniture and refused to work. After some time, she disappeared and no one heard anything from her. As a decent gesture, Stephen looked for a way to provide for her without being attached to her lifestyle. For the previous five years, he paid her money to stay away from him and it worked until now. Bounderby does not have very much advice though he does agree that Blackpool is in a very bad situation. Stephen wants to know how he might be rid of the woman and Bounderby and Mrs. Sparsit are both offended.

Stephen would much rather be with Rachael but what he learns from Bounderby is that any sort of annulment or divorce or separation from the drunk woman is going to cost a good deal of money‹far more than Stephen will ever have.