The Hall effect is exhibited by an electric conductor in the presence of current flow. We report a qualitative deviation. We found the electron fluid in graphene responds to nonquantizing magnetic fields by producing an electric field opposite to that. The viscous contribution is substantial by analyzing voltages that arise in the vicinity of contacts that are current-injecting and recognized. We analyzed the anomaly and pulled the Hall viscosity, a transport coefficient which has been recognized theoretically but remained evasive.